If f(x) = logx3logex2, then f (x) at x = e is from Mathematics J

Subject

Mathematics

Class

JEE Class 12

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

Advertisement

11.

If f(x) = logx3logex2, then f'(x) at x = e is

  • 13e1 - loge2

  • 13e1 + loge2

  • 13e- 1 + loge2

  • - 13e1 + loge2


A.

13e1 - loge2

 fx = logx3logx2           = log2logx3logxOn differentiating wrt x, we get      f'(x) = logx . 12logx . 2x - log2logx1x3logx2 f'(e) = 13e1 - log212 = 13e1 - log2


Advertisement
12.

If f(x) = (x - 2)(x - 4)(x - 6) ... (x - 2n), then f'(2) is

  • (- 1)n2n - 1 (n - 1)!

  • (- 2)n - 1 (n - 1)!

  • (- 2)n n!

  • (- 1)n - 12n (n - 1)!


13.

If θ is semi vertical angle of a cone of maximum volume and given slant height, then tan(θ) is equal to

  • 2

  • 1

  • 2

  • 3


14.

A man of 2 m height walks at a uniform speed of 6 km/h away from a lamp post of 6 m height. The rate at which the length of his shadow increase, is

  • 2 km/h

  • 1 km/ h

  • 3 km/h

  • 6 km/h


Advertisement
15.

If y = 4x-5 is a tangent to the curve y2 = px3 + q at (2, 3), then

  • p = 2, q = - 7

  • p = - 2, q = 7

  • p = - 2, q = - 7

  • p = 2, q = 7


16.

A missile is fired from the fround level rises x metre vertically upwards in t second, where x = 100t - 252t2. The maximum height recahed is

  • 200 m

  • 125 m

  • 160 m

  • 190 m


17.

If the curves x2 = 9A(9 - y) and x2 = A(y + 1) intersect orthogonally, then the value of A is

  • 3

  • 4

  • 5

  • 7


18.

If f (x) = 3x4 + 4x3 - 12x2 + 12, then f(x) is

  • increasing in (- , - 2) and in (0, 1)

  • increasing in (- 2, 0) and in (1, )

  • decreasing in (- 2, 0) and in (0, 1)

  • decreasing in (- , - 2) and in (1, )


Advertisement
19.

In a ABC, if 3 - 1a = 2b, A = 3B, then C is

  • 60°

  • 120°

  • 30°

  • 45°


20.

The x - axis, y - axis and a line passing through the point A (6, 0) from a ABC. If A = 30°, then the area of the , in sq unit is

  • 63

  • 123

  • 43

  • 83


Advertisement