Tuesday, 8 February 2022

Quadratic equations (Short cut Method)

Type:-

** (x+ 7)(x+ 9)= (x +3)(x+ 21).

Here 7x9= 3x21
Therefore x= 0

  EXERCISE -1
    *******

1) (x+ 2)(x+ 10)= (x +5)(x+ 4).

2) (x+ 1)(x+ 10)= (x +2)(x+ 5).

3) (x+ 12)(x+ 9)= (x + 54)(x+ 2).

4) (x+ 12)(x+ 4)= (x +6)(x+ 8).

5) (x+ 20)(x+ 5)= (x +50)(x+ 2).

6) (x+ 21)(x+ 2)= (x +7)(x+ 6).

7) (x+ 18)(x+ 2)= (x +4)(x+ 9).

8) (x+ 700)(x+ 90)= (x +3)(x+ 2100).

9) (x+ 15)(x+ 6)= (x +3)(x+ 30).

10) (x+ 1)(x+ 34)= (x +2)(x+ 17).



TYPE -2;

** 1/(2x -1) + 1/(3x -1)= 0.
Here (2x-1)+(3x- 1)=0
  5x - 2= 0
  x= 2/5

EXERCISE- 2
____________

1) 1/(3x -2) + 1/(2x -1)= 0.

2) 1/(7x -2) + 1/(3x - 5)= 0.

3) 1/(8x - 5) + 1/(13x - 7)= 0.

4) 1/(2x + 3) + 1/(3x + 7)= 0.

5) 1/(x +11) + 1/(x + 12)= 0.

6) 1/(x - 21) + 1/(x - 31)= 0.

7) 1/(2x +9) + 1/(3x +23)= 0.

8) 1/(12x +1) + 1/(3x - 8)= 0.

9) 1/(222x - 7) + 1/(31x - 9)= 0.

10) 1/(87x - 61) + 1/(3x - 9)= 0.

11) 1/(23x + 69) + 1/(42x -1)= 0.

12) 1/(202x - 89) + 1/(32x -19)= 0.

13) 1/(202x - 89) + 1/(32x -19)= 0.

14) 3/(2x - 89) + 3/(3x -9)= 0.

15) 5/(5x - 2) + 5/(x +19)= 0.

16) 1/(3 - 4x) + 1/(7 - 2x) = 0.

17) 1/(1 - 9x) + 1/(8 - 3x) = 0.

18) 1/(2 - 5x) + 1/(7 + 6x) = 0.

19) 1/(30 - 9x) + 1/(2 - 8x) = 0.

20) 1/(7 + 3x) + 1/(9 - x) = 0.

21) 1/(54 - 4x) + 1/(89 - x) = 0.

22) 1/(2021 - x) + 1/(2022 - x) = 0.

23) 1/(309 - 5x) + 1/(709 - 8x) = 0.

24) 6/(1 - 3x) + 6/(2 - 2x) = 0.

25) 1/(67 - 4x) + 1/(67 - 2x) = 0.


EXERCISE-3
************

*** (2x+9)/(2x +7)= (2x+7)/(2x +9).
N' + N" = D' + D"
Then (2x +9)+(2x+7)= 0
Or, 4x +16= 0
Or, x= -4


1) (3x+4)/(6x +5)= (4x+9)/(x +8).

2) (x+ 9)/(6x +5)= (20x+9)/(15x +13).

3) (13x+ 1)/(6x +5)= (14x+9)/(26x +5).

4) (7x+41)/(6x +5)= (41x+9)/(42x +45).

5) (x+41)/(3x +1)= (4x+9)/(2x +49).

6) (2x+ 7)/(6x +5)= (8x+9)/(4x +11).

7) (301x+4)/(205x +5)= (4x+9)/(100x +8).

8) (3x+4)/(6x +7)= (x+ 1)/(2x + 3).

9) (3x+4)/(6x +7)= (5x+6)/(2x +3).


EXERCISE -4
*************

** 1/(x - 7) + 1/(x -9)= 1/(x - 6) + 1/(x - 10).

D' + D" = D"' + D""
2x -16= 0
x= 8



1) 1/(x +7) + 1/(x +9)= 1/(x + 6) + 1/(x +10).

2) 1/(x - 7) + 1/(x +9)= 1/(x +11) + 1/(x - 9).

3) 1/(x - 8) + 1/(x -9)= 1/(x - 5) + 1/(x - 12).

4) 1/(x - 8) - 1/(x - 5)= 1/(x - 12) - 1/(x - 9).

5) 1/(x + 1) - 1/(x +3)= 1/(x +2) - 1/(x + 4).

6) 1/(x + 1) - 1/(x - 3)= 1/(x - 4) - 1/(x - 8).

7) 1/(x - b) - 1/(x - b - d)= 1/(x - c + d) - 1/(x - c).

8) 1/(x + b) - 1/(x + b + d)= 1/(x + c - d) - 1/(x + c).

9) (x - 2)/(x - 3) + (x - 3)/(x - 4)= (x - 1)/(x - 2) + (x - 4)/(x - 5).

10) x /(x - 2) + (x - 9)/(x - 7)= (x + 1)/(x - 1) + (x - 8)/(x - 6).

11) (2x - 3)/(x - 2) + (3x - 20)/(x - 7)= (x - 3)/(x - 4) + (4x - 19)/(x - 5).

12) (3x - 8)/(x - 3) + (4x - 35)/(x - 9)= (2x - 9)/(x - 5) + (5x - 34)/(x - 7).

13) (3x - 13)/(x - 4) + (4x - 41)/(x - 10)= (2x - 13)/(x - 6) + (5x - 42)/(x - 8).

14) (4x + 21)/(x +5) + (5x - 69)/(x - 14)= (3x - 5)/(x - 2) + (6x - 41)/(x - 7).

15) (x²+ 3x +3)/(x +2) + (x² - 15)/(x - 4)= (x²+ 7x +11)/(x +5) + (x² - 4x - 20)/(x - 7).

16) 2/(2x + 3) + 3/(3x +2) = 1/(x + 1) + 6/(6x +7).

17) 3/(3x + 1) - 6/(6x +1) = 3/(3x + 2) - 2/(2x +1).

18) 3/(3x + 1) + 2/(2x -1) = 3/(3x - 2) + 2/(2x +1).

19) 1/(x + 3) + 3/(3x -1) = 1/(x + 5) + 3/(3x -7).

20) (2x +11)/(x + 5) - (9x - 9)/(3x - 4) = (4x +13)/(x + 3) - (15x - 47)/(3x - 10).

21) (5 - 6x)/(3x - 1) + (2x +7)/(x +3) = (31- 12x)/(3x -7) + (4x +21)/(x +5).


EXERCISE - 5
*************

1) x + 1/x = 26/5.                    5, 1/5

2) x/(x+1) + (x +1)/x = 82/9.      1/8, -9/8

3) (x +1)/(x+2) + (x +2)/(x +1) = 37/6.          -11/5, -4/6

4) (x +4)/(x - 4) + (x - 4)/(x +4) = 10/3         8, - 8

5) x + 1/x = 13/6.               3/2, 2/3

6) x+ 1/x = 25/12.            4/3, 3/4

7) (x +5)/(x+ 6) + (x + 6)/(x +5) = 29/10.          -13/3, - 20/3

8) x /(x+ 1) + (x + 1)/x = 169/60.          5/7, - 12/7

9) (2x +11)/(2x -11) + (2x -11)/(2x +11) = 193/84.            

10) x - 1/x = 45/14.             7/2, -2/7

11) x /(x+ 3) -  (x + 3)/x = 15/56.          - 24, - 7/5

12) (x + 7)/(x+ 9) - (x + 9)/(x + 7) = 32/63.          -16, - 63/8

13) (5x +9)/(5x - 9) - (5x -9)/(5x +9) = 56/45          63/10, - 18/35



EXERCISE - 6
**************

*** (2x +6)/(3x+5) = (5x +2)/(4x +3). 
Sum of N = Sum of D
Then, 7x +10= 0 or -3x +4= 0



1) (3x +4)/(6x+7) = (5x +6)/(2x +3).   -5/4, -1

2) (7x +5)/(9x -5) = (9x +7)/(7x +17).   -3/4, 5

3) (3x -9)/(2x- 9) = (9x -7)/(14x -7).   1, 0

4) (16x -3)/(7x+7) = (2x -15)/(11x -25).   1, 10/9



EXERCISE-7
************




  




               







Monday, 7 February 2022

TEST PAPER (INTEGRAL CALCULUS)




P-1
----- 

1) ∫ dx/(1+ sinx).                     tanx - secx

2) ∫(tanx - x) tan²x dx.         1/2 (tanx - x)²

3) ∫ dx/(sin²x cos²x).                 tanx - cotx

4) Integrate log x w.r.to x.                x log x - x

5) ∫ dx/(sinx cosx).             Log|tanx|

6) ∫(sinx + cosx)/√(1+ sin2x).         x
   
7) ∫ Sin 2x/(sin3x sin 5x) dx.        1/3 log|sin 3x| - 1/5 log|sin 5x|

8) ∫ dx/{sin(x - a) sin (x - b)}.   1/sin(x - a). Log|(sin(x - a))/(sin(x - b))|

9) (Sin x+ cosx)/sin(x - a) dx.     (Cos a - sin a)(x - a)+ (cos a + sin a) log|sin(x - a)|

10) ∫ tanx tan 2x tan 3x dx.          1/3 log|sec 3x| - 1/2 log|sec 2x| - log|sec x| 

11) ∫ √tanx/(sinx cosx) dx.    2 √tanx

12) ∫ dx/√(2ax - x²).             sin⁻{(x - a)/a}

13) ∫ dx/{√(x +1)+ ³√(x +1)}.     2√(x +1) - 3 ³√(x +1) + 6 ⁶√(x +1)- 6 log| ⁶√(x +1)+ 1|    

14) ∫ x² dx/{(x² +1)+ (x +1)²}.        1/2 [log|(x -1)|- 1/(x -1) - 1/2 log(x²+1)] 

15) ∫ d(x² -1)/{x√(2 - x²)}.     sin⁻¹√(x² - 1)

16) ∫ dx/(eˣ - e⁻ˣ).                  Tan⁻¹eˣ

17) ∫ (x² + sin²x)sec²x/(1 + x²) dx.     tanx - Tan⁻¹x 

18) ∫ (x + sinx)dx/(1 + cosx).         x tan(x/2) 

19) ∫ xeˣ dx/(x+ 1)².             eˣ/(x+ 1)

20) ∫ log(1+ x²)/(x+ 1)²dx.           (1/2 - 1/(x+ 1)) log(1+ x²) + tan⁻¹x - log|1+ x|

21) ∫ sin⁻¹√{x/(x + a)} dx.         (x+ a) tan⁻¹√(x/a) - √(ax)

22) ∫ sinx/(sinx + cosx) dx.       1/2[x - log|(sinx + cosx)|]

23) ∫ dx/{(2x - 7)√(x²- 7x + 12)} dx.       sec⁻¹(2x -7)  

24) ∫ dx/{(2x - x²)√(2x - x)} dx.     (x -1)/√(2x - x²)

25) ∫ dx/{(x+ a)(x² + a²)}.           1/2a² [log|x + a| - 1/2 log(x²+ a²)+ tan⁻¹(x/a)]

26) ∫ sin(logx) dx.         x/2 [sin(logx) - cos(logx)]

27) ∫ √(1+ cosecx) dx.      2 sin⁻¹{sin x/a - cos x/2)

28) ∫ (cosx + x sinx)/{x(x + cosx)} dx.              Log{x/(x + cosx)}

29) ∫ dx/(cos⁴x - cos²x sin²x + sin⁴x) dx.               Tan⁻¹(tanx - cotx)

30) ∫ ₑtan⁻¹x {(1+ x+ x²)/(1+ x²)} dx.     x ₑtan⁻¹x  

31) ∫ dx/(sin a + sinx) dx.     1/cos a [log|sin(x+ a)/2| - log|cos (x - a)/2|]

32) ∫ (1- x²)dx/{(1+ x²) √(1+ x²+ x⁴)}.       cosec⁻¹(x+ 1/x) 

33) ∫ (x- 1)dx/{(1+ x) √(c+ x²+ x³)}.       2 tan⁻¹(x+ 1/x + 1) 

34) ∫ dx/√(sin³x sin(x+ a).            - 2 cosec a √{sin(x+ a) cosecx}

35) ∫ ₑ sinx [x cosx - secx tanx]dx.    (x - secx) ₑsinx 

36) ∫ (cosx - sinx)/√sin 2x dx.     Log|sinx + cosx + √sin2x|

37) ∫ √tanx dx.                          1/√2 sin⁻¹(sinx - cosx) - 1/√2 log|sinx + cosx + √sin2x|


Friday, 4 February 2022

EXACT DIFFERENTIAL EQUATIONS

EXACT DIFFERENTIAL EQUATION
              ****** ******* *******
Definition:
If M and N are functions of x and y, the equation M dx+ N dy=0….(1)
 is called exact when there exists a function f(x,y) of x 
and y, such that
    d[f(x,y)] = M dx + N dy,. …..(2)
WORKING RULE:
Compare the given equation with
 M dx N dy =0 and find M and N. Then find out dM/dy and dM/dx, if dM/dy=dN/dx, we conclude that the given equation is exact. If the equation is exact, then
Step. 1) Integers M with respect to x treating y as a constant.
Step. 2) Integrate with respect to y only those terms of N which do not contain x.
Step. 3) Equate the sum of these two integrals (found steps 1 and 2) to an arbitrary constant and thus we obtain the required solution. In short the solution of Exact equation
 M dx+ N dy =0 is 
∫ M dx + ∫ (in terms in N not containing x) dy = c. where c is sn arbitrary constant.

Example. 1 : 
1)(x²-4xy-2y²)dx + (y²-4xy-2x²)dy=0
here M= x²-4xy-2y² and N=y²-4xy-2x²
 dM/dy= -4x-4y and dN/dx= -4y-4x
so that dM/dy= dN/dx
hence, the given equation is exact hence its solution is.
∫ M dx + ∫(terms in N not containing x) dy = c′
∫(x² -4xy -2y²)dx + ∫y² dy =c′
x³/3 -4y(x²/2)-2y²x + y³/3 = c/3  
                                 taking c′ = c/3
Example. 2)
(2x-y+1)dx + (2y-x-1) dy= 0
comparing Mdx +N dy=0
M=2x-y+1 N= 2y-x-1
dM/dy= -1= dN/dx hence exact
∫M dx(treating y as constant) +∫(terms in N not containing x)dy =c
∫(2x-y+1)dx + ∫(2y-1)dy=0
or x² - xy+x -y² -y =c 

                    EXERCISE 
1)(4x+3y+1) dx +(3x+2y+1) dy =0

2) dy/dx = (2x-y+1)/(x+2y-3)

3) (1+eˣ/ʸ)dx + eˣ/ʸ {1-(x/y)} dy = 0

4) ₍ᵥ2ₑxy² ₊₄ₓ³₎dx ₊ ₍₂ₓᵥₑxy² ₋ ₃ᵥ²₎dy ₌ ₀

5) (ax +by+g) dx +(hx+ by +f)dy =0

6) {y(1+ 1/x) + cos y}dx + {x+ log x -x siny) dy = 0

7) xdx+ydy +(x dy - y dx)/(x² + y²)= 0 

8) x dx + y dy= a²(x dy -y dx)/(x² +y²)

9) (x dy + ydy)(x² +y²) = a²(x dy - ydx)

10) (x³+xy²+a²y)dx +(y³+yx²-a²x)dy=0

11) (x²+y²)(xdx+ydy)=xdy - ydx.

12) (r+sinθ - cosθ)dr + r(sinθ+cosθ)dθ=0

13) y sin 2x dx -(1+y²+cos²x) dy=0

14) y sin 2x dx - (y² + cos²x) dy = 0

15) (x² +y² +x)dx - ((2x² +2y² -y)dy=0

16) (4x +3y +1) dx +(3x+2y+1) dy=0

17) Find the value of constant K such that (2xeʸ +3y²)(dy/dx)+(3x²+ Keˣ)=0 is a exact . further, for this of K solve the equation.

18) (x+2y -2)dx + (2x-y+3) dy=0

19) (2ax+by)ydx + (ax+2by)x dy=0

20) (x²- ay)dx = (ax -y²) dy

21) dy/dx = (2x -y)/(x+2y - 5)

22) (x² +y² +a²)y dy +(x²+y²- a²)dx=0

23) (eˣ +1) cos x dx+ eʸsinx dy =0

24) x(x² + 3y²)dx + y(y²+3x²)dy =0

25) (a² - 2xy -y²) dx - (x+y)² dy =0

26) (3x² +6xy²) dx + (6x²y²+ 4y³)dy=0

27) (x⁴-2xy²+y⁴)dx - (2x²y -4xy² +siny) dy =0

28) (3x² + 4xy)dx + (2x² + 2y) dy =0





Wednesday, 2 February 2022

QUICK SOLVE:


1) 119/x = 271/60.

2) 73/91 = 98/x

3) x/540 = 237/681.

4) 538/x = 173/71.

5) 961/384 = x/283.

6) 161/39 = 51/x.

7) 273/37 = x/29.

8) 3146/293 = 1837/x.

9) 639/123 = x/235.

10) 379/2348 = x/1131

11) x/843 = 6384/1853

12) 1337/431 = 863/x

13) 301/x = 961/323

14) x/423 = 765/306.

15) 523/418 = x/239.

16) x/317 = 523/174.

17) x/179 = 216/643.

18) 634/x = 217/760.

19) 331/173 = 661/x

20) x/237 = 739/478

21) x/157 = 490/326

22) x/174 = 1864

23) x/416 = 1/585

24) x/1334 = 17/667

25) 34/134 = 100x/15008

26) 80/53 = x/31 

27) 39/29 = x/41

28) 91/36 = x/476

29) 32/209 = x/638

30) 459/152 = x/380

31) 39/18= x/271

32) 4x/35 = 440/19

33) 18/29 = 41/x

34) 16/59= 73/x

35) 293/399= 693/x

36) x/12 = 501/792

37) 864/63 = x/294

38) x/12 = 16/215

39) 187x/221 = 247/2197

40) x/102 = 684/225

41) 49/235 = x/48

42) x/108 = (127² - 19²)/216²

43) 1111/x = 12344321/8

44) 12/649 = x/507

45) 153/47 = x/53

46) x/123 = 131/205

47) x/100 = 282/825

48) x/749 = 3748/1249

49) x/159 = 53/83

50) 19/297 = x/142

51) 30/97 = x/107

52) 24/75 = x/88

53) 126/x = 375/658 (to the nearest integer)

54) 33/63 = 39/x

55) 72/x = x/338

56) 87/260 = 162/x

57) 275/640 = x/525

58) 343/x = 1375/228

59) 323/452 = 685/x (nearest integer)

60) 67/837 = 91/x

61) 47/140 = x/237

62) 69/x = 112/504

63) 185/246 = 93/x

64) 274/411 = x/221

65) 353/181 = 612/x

66) 64/x = 17/37

67) 23/63 = x/84

68) 92/47 = 113/x

69) (x +14)/162 = 19/23

70) 63/28 = x/52

71) x/201 = 375/621

72) 231/x = 123/419


Tuesday, 1 February 2022

QUICK MULTIPLICATION

1) 64 x 3158.

2) 216 x 839.

3) 338 x 567

4) 1236 x 3548

5) 1322 x 5411

6) 568 x 796

7) 328 x 422

8) 764 x 166

9) 1012 x 98

10) 564 x 636

11) 397 x 403

12) 784 x 125

13) 378 x 572

14) 3641 x 836

15) 567 x 438

16) 863 x 908

17) 639 x 521

18) 3863 x 867

19) 621 x 536

20) 777 x 649

21) 1728 x 144

22) 623 x 548

23) 563 x 484

24) 287 x 329

25) 846 x 568

26) 398²

27) 1008²

28) 503²

29) 132²

30) 484² - 316²

31) 593 x 607

32) 10.12²

33) 492 x 509

34) 369 x 523

35) 392²

36) 14.85²

37) 253 x 247

38) 1372 x 125

39) 356 x 248

40) 791 x 295

41) 1250 x 842

42) 484 x 238

43) 264²

44) 596²

45) 837 x 555

46) 239 x 251

47) 168 x 192

48) 208 x 207

49) 385 x 563

50) 999 x 375

51) 2113 x 2117

52) 1564 x 525

53) 1831 x 1769

54) 583 x 621

55) 239 x 357

56) 489 x 351

57) 283 x 461

58) 560 x 625

59) 117²

60) 347 x 525

61) 69²

62) 318 x 336

63) 103 x 301

64) 249 x 261

65) 1421 x 179

66) 478 x 563

67) 888 x 555

68) 347 x 373

69) 1111 x 111

70) 6832 x 375

71) 7869 x 982

72) 892 x 404

73) 5324 x 136

74) 331 x 339

75) 414²

76) 188 x 202

77) 5555 x 2222

78) 156 x 161

79) 61 x 79

80) 175 x 825

81) 287 x 41

82) 3774 x 383

83) 233 x 287

84) 1007 x 1014

85) 819 x 918

86) 235²

87) 246 x 258

88) 84 x 126

89) 644 x 72

90) 981 x 992

91) 473²

92) 213 x 148

93) 363 x 383

94) 2347 x 11

95) 3456 x 12

96) 4216 x 875

97) 4444²

98) 1531²

99) 1248 x 256

100) 163 x 168

101) 784 x 46

102) 174 x 264

103) 9983 x 984

104) 432 x 189

105) 464 x 446

106) 287 x 427

107) 576²

108) 525 x 175

109) 288x 18

110) 1158 x 32

111) 126²

112) 891² + 819²

113) 4182 x 2814

114) 88888 x 5555

115) 547 x 126

116) 748 x 528

117) 128 x 74

118) 813 x 719

119) 275²

120) 146²

121) 819 x 918

122) 172 x 127

123) 432 x 342

124) 126 x 174

125) 182 x 128

126) 169 x 961

127) 426 x 684

128) 136 x 464

129) 743 x 763

130) 24³ x 18³

130) 9819 x 181

131) 308²

132) 324² + 576² + 324 x 576

133) 786 x 224

134) 156 x 166

135) 172 x 179

136) 9728 x 10272

137) 10³ - 18³

138) 871 x 178

139) 1962²

140) 299 x 899

141) 2025 x 3025

142) 1255 x 7750

143) 131² + 169²

144) 1024² - 576²

145) 1012 x 984

146) 991 x 983

140) 3725 x 3775

141) 1667²

142) 813 x 887

143) 738 x 84

144) 945 x 1055

145) 726 x 772

146) 284 x 516

147) 984 x 94

148) 556 x 655

149) 993 x 96

150) 68 x 132

151) 209 x 231

152) 486 x 243

153) 994 x 1008

150) 307 x 333

151) 93 x 1024

152) 997 x 994

153) 538 x 492

154) 612 x 268

155) 991 x 994

156) 342 x 684

157) 654 x 123

158) 6³

159) 127²

160) 39² - 27²

161) 472 x 107

162) 472 x 107

163) 325 x 425

164) 645  x  15 

165) 625  x 375 

166) 984  x 988 

167) 152  x 153 

168) 491²

169) 228  x 420

170) 613 x  34

171) 499  x 8230

172) 45² - 30²

173) 991  x 1009

174) 1004  x 972 

175) 496  x 375 

176) 1828  x 59

177) 444 x  720 

178) 1123  x 43

179) 78  x 92 

180) 152²

181) 94  x 994 

182) 235  x 265 

183) 72² - 48²

184) 79  x 91 

185) 126  x 621 

186) 993  x 890 

187) 48  x 1023

188) 480  x 620 

189) 144  x 1728 

190) 93 x 97

191) 135  x 490

192) Thousand's digit of the product 384 x 857 is

193) 1009 x 994 

194) 375  x 1684 

195) 1276  x 1324 

196) 75² - 65²

197) 212²

198)  384  x 673 

199) 175  x 425 

200) 513  x 1008

201) 556  x 634 

202) 666  x  777 

203) 97 x 73 

204) 363  x 504 

205) 986  x 992 

206) 153²

207)  672  x 355 

208) 445 x 312 

209) 907  x 617 

210) 774  x 688 

211) 378  x 196 

212) 378  x 576 

213) 634  x 783

214)  167  x 349 

215) 214  x 487 

216) 167  x 1421 

217) 632  x 421 

218) 143  x 321 

219) 728  x 296

220) 241  x 233 

221) 678  x 665 

222) (367  x 123) - 1234.

223) (378  x 12) -  234.

224) (6 + 342 + 1296) -  2364/4

225) (281  x 362) + 1237.

226) 334  x 672.

227) 196  x 195.

228) 238  x 742

229) 231  x 122.

230) 123  x  431.

231) 622  x 729.

232) 823  x 863

233) (342  x 631) -  (621  x 334)

234) (213  x 414) - (316  x 203)

235) 632  x 498

236) 412²

237) 788²

238) 313 x  896

239) 313   x 896

240) 673   x 432

241) The square of 738

242) The square of 651.

243) 123  x 638 

244) 341  x 441 

245) 678 x  734 

246) 96 x 431 

247) 112  x 116

248) 312  x 463

249) 773  x 482 

250) 654  x 567 

251) 127  x 963 

252) 86 x 93 

253) 621  x 342 

254) 732  x 123 

255) 129 x 632 

256) 1024  x 128 

257) 1024  x 128

258) 134  x 872 

259) 128²

260) 63²

261) 239²

262) 378  x 444 

263) 638  x 428 

264) 991  x 199 

265) 663  x 369 

266) 483  x 834 

267) 889  x 463

268) 342  x 985 

268) 124  x 638 

269) 442  x 741 

270) 63 x 431 

271) 621  x 342 

272) 732  x342

273) 732   x 123

274) 129  x 632

275) 1024 x 128

276) 134 x 872

277) 889 x 463

278) 342 x 985

279) 124 x 638

280) 442 x 741

281) 342 x 768 

282) 989  x 898 

283) 432  x 324 

284) 588  x 858 

285) 906 x  609





Saturday, 20 November 2021

QUICK REVISION (XII)

REVISION
LINEAR PROGRAMMING
--------------------------

SOLVE GRAPHICALLY:

1) 3y - 2x < 4, x+ 3y > 3 and x + y≤ 5.

2) 2x + y- 3 ≤ 0, 2x+ y- 6 > 0.

DETERMINE THE MAXIMUM AND MINIMUM VALUES:

1) f(x,y)= 3x + 5y, vertices at (4,8), (2,4), (1,1),(5,2).     
          Max 52 at (4,8), Min 8 at (1,1)

2) f(x,y)= x + 4y, vertices at (0,7), (0,0), (5,4),(6,2).     
          Max 28 at (0,7), Min 0 at (0,0)

3) Z= x+ 3y subject to x,y ≥0, 5x + 2y≤ 20, 2y ≥ x.   
        Max 30 at (0,10), Min 0 at (0,0)

4) f(x,y)= 10x + 12y, subject to x, y ≥ 0, 2x + 5y ≥22, 4x + 3y ≥ 28, 2x + 2y ≤ 17.     
    Max 97 at (5/2,6), Min 562/7 at (37/7,16/7)

5) 5x + y≥ 10, x + y ≥ 6, x + 4y≥ 12, x≥ 0, y ≥0. Z= 3x + 2y         min 13 at (1,5)

6) x - y≤ - 1, - x + y ≤ 0, x≥ 0, y ≥0. Z= 3x + 4y                  no solution exists

7) A shopkeeper deals in two items - wall hangings and artificial plants. He has ₹15000 to invest and a space to store at most 80 pieces. A wall had hanging costs him ₹300 and an artificial plants ₹150. He can sell a wall hanging at a profit of ₹50 and an artificial plant at a profit of ₹ 18. Assuming that he can sell all the items that he buys, formulate a linear programming problem in order to maximise his profit.      

8) A housewife wishes to mix together two kinds of food X and Y in such a way that the mixture contains at least 10 units of vitamins A.12 units of Vitamin B and 8 units of Vitamin C. The vitamin contents of one kg of foods X and Y are as below:
                Vit A       Vit B        Vit C
Food X     1              2              3
Food Y     2              2              1
One kg of food X costs ₹6 and 1 kg of food Y costs ₹10. Formulate the above problem as a linear programming problem, and use iso- cost method to find the least cost of the mixture which will to produce the diet.                                Min ₹52

9) A man has ₹1500 for purchase of rice and wheat. A bag of rice and a bag of wheat cost ₹180 and ₹120, respectively. He has storage capacity of 10 bags only. He earns a profit of ₹ 11 and ₹9 per bag rice and wheat respectively. Formulate an LPP to maximize the profit and solve it.                  5 rice bags and 5 wheat bags, Max. Profit=₹100

1p) A manufacturer makes two types of the tea-cups, say, A and B. Three machines are needed for their manufacturing and the time (in minutes) required for each Cup on the Machine is given below:
Cup                Machine
                I              II                III
A            12           18               6
B              6             0                9
Each machine is available for a maximum of 6 hours per day. If the profit on each Cup A is 75 paise and on each cup B is 50 paise, show that 15 tea- cups of  type A and 30 of type of B should be manufactured in a day to get maximum profit.    

11) A factory owner purchases two types of machines. A and B, for his factory. The requirements and  limitations for the machines are as follows:
Machine   Area       labour   daily
             occupied     force    output
                 by the         each      on
              machine   machine  units
A           1000 sq.m   12 men    60
B           1200 sq.m    8 men     40
He has an area 9000 sq.m available and 72 skilled men who operate the Machines. How many Machines of each type should he buy to maximize the daily outputs ?        4 type A, 3 type B or 6 type A, no machine of type B.

12) A dietician wishes to mix two types of food in such a way that the vitamin contents of the mixture contain atleast 8 units of Vitamin A, and 10 units of Vitamin C. Food I contains 2 units/kg of Vitamin A and 1 unit/kg of vitamin C. Food II contains 1 unit/kg of Vitamin A and 2 unit/kg of Vitamin C. It costs ₹5  per/kg to purchase food I and ₹7 per/kg to purchase Food II. Determine the minimum cost of such a mixture.                 2 kg food I, 4 kg of Food II. Min cost= 38

13) A factory manufacturer produces two types of screws. A and B each types  requiring the use of two machines - an automatic and a hand operated. it takes 4 minutes on the automatic and 6 minutes on the hand operated machine to manufacture a package of screws A. while it takes 6 minutes on the automatic and 3 minutes on the hand operated machine to manufacture a package of screws B, each machine is available for atmost 4 hours on any day. The manufacturer can sell a package of screws A at a profit of ₹7 and of screws B at a profit of ₹10. Assuming that he can sale all the screws he can manufacture, how many package of each type should the factory owner produce in a day in order to maximize profit ? Determine the maximum profit.                      Max profit ₹410 at (30,20)

14) A brick manufacture has two depot A and B, with stocks of 30000 in 20000 bricks respectively. He receives a orders from three builders P, Q and R for 15000, 20000 and 15000 respectively. The cost (in Rs) of transporting 1000 bricks to the builders from the depot are given below:
To/from   Transport cost per
                  1000 bricks (in Rs)
               P        Q.        R
A           40      20        20
B           20      60        40
The manufacturer wishes to find how to fulfill the the order so that transportation cost is minimum.
Formulate L. P. P.     

15) A company has two factories located at P and Q and has three depots situated at A, B and C. The weekly requirement of the depot at A, B, C is respectively 5, 5 and 4 units, while the production capacity of the factories at P and Q are respectively 8 and 6 units. The cost of transportation per unit is given below:
To/from.        Cost(in Rs)
                    A           B           C
P                16         10         14
Q.               10         12         10
How many units should be transported from each factory to each depot in order that the transportation cost is minimum.    






REVISION
MEAN THEOREM & TANGENT AND NORMAL
_______________&&&&_____________

1) Use lagrange's mean value theorem to determine a point P on the curve y= √(x² - 4) defined in the interval [2,4] where the tangent is parallel to the chord joining the end-points on the curve. (√6, √2)

2) Verify Rolle's theorem for the function f(x)= e ²ˣ(sin2x - cos 2x) defined in the interval [π/8, 5π/8].  

3) Given f(x)= (x - 3)log x prove that there is atleast one value of x in the interval [1, 3] which satisfies the equation x log x = 3 - x

4) Examine the validity and conclusion of Rolle's theorem for the function
f(x)= eˣ sin x, ∀ x ∈ [0, a] 

5) Examine the validity and conclusion of lagrange's mean value theorem for the function f(x)= x(x - 1)(x - 2) for every x ∈ (0, 1/2). Not acceptable

6) Verify Rolle's theorem for the function f(x)= log{(x² + ab)/(ax+ bx)} x ∈ [a, b] and 0 not belongs to [a,b]

7) Verify Rolle's theorem for the function f(x)= sinx + cos x - 1 in [0, a/2] and find the point where the derivation vanishes. π/4

8) Show that the function f(x)= x² - 6x + 1 satisfies the Lagrange's mean value theorem. Also find the coordinates of a point at which the tangent to the curve represent by the above function is parallel to the chord A(1, -4) and B(3, -8). B b(2, -7)

9) Verify lagrange's mean value theorem for f(x)= sinx - sin2x in [0,π].    

10) Verify Rolle's theorem for f(x)= x(x +3) e⁻ˣ⁾² [-3, 0].

11) Verify Lagrange's mean value theorem for the following function f(x)= 2x - x², 0≤x≤ 1

12) Check if Lagrange's mean value theorem is applicable to f(x)= 4 - (6 - x)²⁾³ in [5, 7].

13) Find c of the Lagrange's mean value theorem for the function f(x)= x(x - 2) in the interval to [1,2]. 3/2

Tangent and Normal


1) Find the point on the curve 9y²= x³, where the normal to the curve makes equal intercepts on the axes.

2) Find the Equations of the tangent to the curve x= sin 3t, 
y= cos 2t at t= π/4

3) Find the slope of the tangent to the curve y= 3x² - 6 at the point on it whose x-ordinate is 2.

4) Find the Equation of the tangent to the curve y= x⁴-6x³+13x²-10x+5 at the points x=2, y=0

5) The equation of the tangent at
(2,3) on the curve y²=ax³+b is.  y=4x-5. Find the values of  a and b.

6) Find the equation of tangents to the curve y=cos(x+y), - 2π ≤ x ≤ 2π that are parallel to the line x+2y=0 

7) If the tangent to the curve y= x³+ax+b at (1, - 6) is parallel to the line x - y + 5=0 find a, b.

8) Find the Equation of the tangent to the curve x= sin 3t, y= cos 2t at t=π/4. Show that the curves 2x= y² and 2xy = k cut right angles If k² = 8.

9) Find the Equation of tangent lines to the curve y= 4x³ - 3x +5 which are perpendicular to the line 9y+x+3=0.








                         



     







1) Solve: cos(sin⁻¹x)= 1/7.    ±4√3/7

2) Use Matrix rule to solve 2x+ 3y= 10 and x+ 6y= 4.               16/3, -2/9

3) Find dy/dx if y+ sin y= x².           x sec²(y/2)

4) Let f: X --> be a function defined on a relation R on X is given by R={(a,b): f(a)= f(b). Show that R is an equivalence relation on X.   

5) If f: R--> R is defined by f(x)= (3 - x³)¹⁾³. then find f of(x).                   x

6) consider f: R₊ -->[-9, ∞] given by f(x)= 5x²+6x-9, prove that f is invertible with f⁻¹(y)={√(54+5y) -3}/5.    

7) Value of tan(2 tan⁻¹ 1/5).     5/12

                                       √x...∞
                                  √x
8) Differentiate: √x     with respect of x .                         y²/{x(2- log x)}

9) solve for x if x²     x     1 
                           0      2     1 = 28
                           3      1     4    -17/7, 2

10) Inverse of:
   -2     5                     -4/23       5/23
    3     4                      3/23       2/23

11) Using Matrix rule to solve the system of equation: 5x+ 7y =-2 and 4x + 6y =-3.                        9/2, -7/2

12) solve x: cos⁻¹x+ sin⁻¹(x/2)=π/6.        ±1

13) dy/dx of cos⁻¹{√(1-cos x)/2}with respect to x.               -1/2

14) If f is an invertible function defined as f(x)= (3x-4)/5, then find f⁻¹(x).                                    (5x+4)/3

15) If y=√{1-cos 2x/(1+cos 2x)}, find dy/dx.                                Sec²x

16) A company wants to launch a new product. it invested ₹37500 as fixed cost of production. The revenue function for the sale of x units is given by 4825x - 125x². Find break even points.                   12,25

17) Does the Lagrange's mean value theorem apply to f(x)= ³√x; -1≤ x ≤ 1 ?                                            No

18) If sin⁻¹x + sin⁻¹y= 2π/3 then find the value of cos⁻¹x + cos⁻¹y.       π/3

19) If y= tan⁻¹[{√(1+x²)-1}/x] then find dy/dx.                        1/{2(1+x²)}

20) Using determinant, Find the value of x, such that points (02), (1,x) and (3,1) are collinear.         5/3

21) if f(x)= 27x³ and g(x)= ³√x, then find g o f(x).                                    3x

22) If f: R--> R defined by f(x)=(3x+5)/2 is an invertible function, then find f⁻¹(x).                     (2x-5)/3

23) Without expanding the determinant show that
1     a        b+c 
1     b        c+a = 0.
1     c        a+b 

24) Using determinants show that the points (11,7), (5,5), (-1,3) are collinear.

25) The regression equation of Y on X is 3x- 5y= 13 and the regression equation of X on Y is 2x- y= 7. Estimate the value of x when y = 10.
  8.5

26) If eˣ + eʸ = eˣ⁺ʸ, prove that dy/dx + eʸ⁻ ˣ = 0.

27) Differentiate xˣ w.r.t.x.       xˣ(log x+1)

28) Find the local maxima and minima for the function x³ -12x.
            Min. at x=2 value: -16. Max at x=-2, value 16

29) If y= x + tan x, prove that cos²x d²y/dx² - 2y + 2x = 0.

30) lim ₓ→₃ (x⁴-81)/(x-3).           108

31) find dy/dx if y tan x - y² cos x + 2x = 0.                   (y sec²x + y² sin x +2)/(2y cos x - tan x).

31) Out of the following two regression line of regression of y on x; 3x+ 12y= 9, 3y+ 9x= 46.          3x + 13y= 9

32) Solve: 7x= 6y-8 and 13y= 9 + 5x by find Matrix method.    -7/9, 23/54

33) If A= 5       3
               -1      -2 find A⁻¹.   2/7   3/7
                                             -1/7  -5/7

34) verify rolle's theorem for the function f(x)= sin x in the interval (π/4, 3π/4).         

35) find the inverse of the matrix
1      2                          7      -2
3      7                         -3       1

36) The function f(x)= x⁴ - 62x² + Kx +9 attains its maximum value on the interval [0, 2] at x= 1. find the value of k.                                120

37) If y= 2 sin x + 3 cos x, find the value of d²y/dx² + y.                    0

38) Using metrix method, solve the following system of equations: 6x+ y - 3z= 5; x+ y - 2z= 5; 2x+ y + 4z= 8;            1, 2, 1

39) without expanding the determinant prove that
x+ y     y+ z       z+x
  z           x            y = 0
  1           1           1

40) If A= x 4 1 & B= 2     1     2
                                  1      0     2
                                  0      2    -4 and C= x
      4
     -1 then ABC= 0 then x is.       -2,-1

41) differentiate cos⁻¹{(1-x²)/(1+x²) with respect to x.                 2/(1+x²)

42) Using determinants prove that (11,7),(5,5) and (-1,3) are collinear.

43) If A=3 and B= 1    -5     7
               1
              -2 then verify (AB)'= B' A'

44) Find the coefficient of correlation between x and x, when Cor(x,y)= -16.5,.Var(x)=2.89 and Var(y)= 100.                                -0.97

45) The fixed cost of a new product is ₹18000 and the variable cost per unit is 550. If the demand function is p(r)= 4000 - 15x, find the break-even points.                              8,15

46) If y= √x + 1/√x, show that 2x dy/dx + y= 2 √x.

47) Among all points a positive numbers with sum 24. Find those whose product is maximum.   12,12

48) If x √(1+y) + y√(1+x)= 0, prove that dy/dx= -1/(1+x)²

49) If y√(1-x²) + x√(1- y²) = 1, prove that dy/dx= √{(1-y²)/(1-x²)}.

50) If sin y= x sin(a+y), prove that dy/dx= {sin²(a+y)}/sin a.

51) If ax² + 2hxy + by²+ 2gx + 2fy + c= 0, Find dy/dx.                               -{(ax+by+g)/(hx+ by+f)}

52) The demand function of a monopolist is given by P= 1500 - 2x - x². Find the marginal revenue for any level of output x. Also, find marginal revenue(MR) when x= 10.
           MR= 15004x-3x², .R= 1160

53) Find regression coefficients bᵧₓ and b ₓᵧ if ∑x=30, ∑y= 42, ∑xy= 199, ∑x²= 184, ∑y²= 318 and n= 6. Also , find p(X,Y).       -0.323, 0.458, -0.384

54) Show 1+ x      1        1 
                  1        1+ x      1 =x²(x+3)   
                  1          1       1+x  

55) Using Matrix method solve: 2x- 3y= 1, x+ 5y= 7.                          2, 1

56) find the interval in which the function f(x)= x³ - 12x² +36x +17 is an increasing or decreasing function.          Inc(-∞,2) and (6, ∞) and Dec [2,6]

57) Find the point of the curve 9y² = x³, where the normal to the curve makes equal intercepts on the axis.            (4, 8/3) & (4, -8/3)

58) find the equation of the tangent to the curve x= sin 3t, y= cos 2t at t= π/4.                            6√2 x - 8y-2= 0

59) Find the slope of the tangent to the curve y= x⁴ - 6x³ + 13x² - 10x+5 at the points x=1, y=0.          2x-y= 2

60) It is given that for the function f(x)= x³ + bx² + ax +5 on [1,3] , Rolle's theorem holds with C= 2 + 1/√3. find the values of a and b.     11, -6

61) If y= sin[2tan⁻¹√{(1-x)/(1+x)}], prove that dy/dx= - x/√(2- x²).      

62) differentiate Cos⁻¹{x - x⁻¹)/(x + x⁻¹)} w r.t.x. -2/(1+x²)

63) Find the maximum value of
1              1             1
1          1 + sin x     1
1             1          1+ cos x.           1/2

64) Matrix A= 0      2b     -2 
                         3       1       3 
                        3a      3      -2 is given to be symmetric, find the values of a, b.           -2/3, 3/2

65) If A= 3    1
                7    2 find A⁻¹ and hence, Solve the following equestions: 3x+7y= 4, x + 2y= 1.    -2   1
                                       7   -3,  -1,1

66) find inverse of the matrix of:
Cos x         Sin x           cos x  - sin x
- sin x         cos x           sin x    cos x

67) Two lines of regression are given by x+ 2y= 5, 2x+ 3y= 8. calculate mean of x and y. regression coefficients of x on y and y on x.        1, 2, -1/2, -3/2, -√3/2

68) If y = tan⁻¹{4x/(1+5x²) + tan⁻¹{(2+3x)/(1+5x²), find dy/dx.
     5/(1+ 25x³)

69) If cos⁻¹x + cos⁻¹y+ cos⁻¹z=π, prove that x²+ y²+ z² +2xyz= 1.

70) Prove sin⁻¹12/13 + cos⁻¹4/5+ tan⁻¹63/16=π. 

** Evaluate:

71) lim ₓ→₀ (sin x - x + x³/6)/x³.     0

72) lim ₓ→₀(xeˣ - log(1+x))/x².    3/2

73) lim ₓ→₀ {log(1+x³)}/sin³x.         1

74) lim ₓ→₀(tan⁻¹x - x)/(sin x - x).   2

75) lim ₓ→₀ (x - sin x)/x³.             1/6

76) lim ₓ→₀{1+ sin x - cos x + log(1-x)}/(x tan²x).                            -1/2


77) Find the value of K if A=1     2 
                                                 2     3 and A² - KA - I= 0.                            4

78) Solve: cos⁻¹sin(cos⁻¹x)π/6.    ±1/2



Monday, 11 October 2021

MATH TEST PAPER (XII) -3


1) If two rows or two columns of a determinant are identical then value of the determinant is:
A) 0        B) 2       C) -1         D) 1 

2) The value of tan(π/2 - tan⁻¹1/3) is equal to 
A) 1/3     B) 3      C) 2/3       D) 3/2 

3) The domain for which the functions f(x)= 3x² - 2x and g(x)= 3(3x -2) are equal, will be..
A){1,2/3} B) {1,3} C) {2/3,3} D) {2/3,0} 

4) If y= tan⁻¹{(5-x)/(1+5x)}, then value of dy/dx=? 
A) -1/(1+x²) B) 1/(1+x²) C) 5 D) 5/(1+x²).

5) Solve: 2 sin⁻¹x= cos⁻¹x, 0<x<1.
A) 1/2 B) 1/3 C) 1 D) none

6) Let A={1,2,3}. Define a relation (on A) which is reflexive and symmetric but not transitive. 
A) (2,2),(3,3),(2,3),(1,2),(2,1)
B) (1,1),(2,2),(3,3),(2,3),(1,2),(2,1)
C) (1,1),(2,2),(3,3),(2,3),(1,2)
D) (1,1),(2,2),(3,3),(1,2)

7) If A= 8      0   &  B= 2      -2
              4     -2            -5       1 find another matrix X where 2A + 3X = 5B.
A) 2    10/3       B) -2       10/3
    11        3            -11         3 
C) -2    -10/3     D) -2        -10/3
    -11        3            11          -3 

8) If 2      3 =  x      3
        4      5    2x     5. Find the value of x.
A) 0       B) 1     C) -2       D) 2 

9) If y= sin⁻¹{2x/(1+x²) then dy/dx
A) 1/(1+x²) B) -1/(1+x²) C) 2/(1+x²) D) -2/(1+x²)

10) f(x)= 5 - | x - 1 |. Find the maximum value of f(x). Also find the value of x for which f(x) is maximum.
A) -5, -1  B) 5, 1  C) 1, 5  D) -1,-5 

11) If R₁ and R₂ are two equivalence relation defined on set A(≠ 0), then R₁∩R₂ is an
A) one-one function
B) onto function
C) equivalence relation
D) none 

12) If tan⁻¹x + tan⁻¹y + tan⁻¹z=π/2 and x+y+ z =√3, then.
A) x=y≠z B) x≠y≠z C) x≠y=z D) x= y=z.

13)     1      2       2
If A=   2     1        2
           2     2        1 then A²-4A= ?
A) 5      B) 4       C) 3         D) 1 

14) Solve: 3x+y+z=20; 3x+y-z= 0; 5x- 9y= 1;
A) 1,2,3  B) 2,1,3  C) 3,2,1  D) 1,3,2

15) If cos y= x cos(a+y), (a≠0), then dy/dx is
A) cos{(a+y)}/sin a 
B) cos a/sin (a +y)
C) cos²{(a+y)}/sin a 
D) sin²{(a+y)}/cos a 

16) If x= sin t, y= sin kt (k≠0, constant) then (1-x²) d²y/dx² - x dy/dx =?
A) - ky    B) -ky²  C) -k²y   D)- k²y² 

17) Find maximum and minimum values of (x²-x+1)/(x²+x+1).
A) -3, 1/3 B) -3, -1/3 C) 3, -1/3 D) 3, 1/3