The function fx = 2x2 - 1,  &n

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

751.

If xexy + ye- xysin2x, then dydx at x = 0 is

  • 2y2 - 1

  • 2y

  • y2 - y

  • y2 - 1


752.

If y = tan-12x - 11 + x - x2, then dydx at x = 1 is equal to

  • 12

  • 23

  • 1

  • 32


753.

If f(x) = cos-12cosx + 3sinx13, then [f'(x)]2 is equal to

  • 1 + x

  • 1 + 2x

  • 2

  • 1


754.

If u = tan-11 - x2 - 1x and v = sin-1x, then dudv is equal to

  • 1 - x2

  • - 12

  • 1

  • - x


Advertisement
755.

If y = 11 + x + x2, then dydx is equal to

  • y2(2 + 2x)

  • - 1 + 2xy2

  • 1 + 2xy2

  • - y2(1 + 2x)


756.

If g(x) is the inverse of f(x) and f'(x) = 11 + x3, then g'(x) is equal to

  • g(x)

  • 1 + g(x)

  • 1 + {g(x)}3

  • 11 + gx3


757.

If y = f(x2 + 2) and f'(3) = 5, then dydx at x = 1 is

  • 5

  • 25

  • 15

  • 10


758.

Let, f(x) = x2 + bx + 7. If f'(5) = 2f'72, then the value of b is

  • 4

  • 3

  • - 4

  • - 3


Advertisement
759.

If y = sin-12x1 - x2, - 12  x  12, then dydx is equal to

  • x1 - x2

  • 11 - x2

  • 21 - x2

  • 2x1 - x2


Advertisement

760.

The function fx = 2x2 - 1,     if 1  x  4151 - 30x, if 4 < x  5 is not suitable to apply Rolle's theorem, since

  • f(x) is not continuous on [1, 5]

  • f(1) f(5)

  • f(x) is continuous only at x = 4

  • f(x) is not differentiable at x = 4


D.

f(x) is not differentiable at x = 4

Given, fx = 2x2 - 1,     if 1  x  4151 - 30x, if 4 < x  5

Differentiability at x = 4,

LHD = limh0f4 - h - f4- h       = limh024 - h2 - 1 - 2 × 16 - 1- h      = limh0216 + h2 - 8h - 32- h      = limh02hh - 8- h      = limh0- 2h - 8 = 16RHD = limh0f4 + h - f4h        = limh0151 - 304 +h - 2 × 16 - 1h        = limh0- 30hh = - 30

 LHD ≠ RHD

Hence, f(x) is not differentiable at x = 4.


Advertisement
Advertisement