Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

If f(x) is differentibale and $\int_0^{t^2} xf(x)dx =\frac{2}{5}t^5$ then $f(\frac{4}{25})$ equals

Options:

2/5

-5/2

1

5/2

Correct Answer:

2/5

Explanation:

$\int_0^{t^2} xf(x)dx =\frac{2}{5}t^5$

differentiate both side w.r.t. t

$t^2\, f(t^2)\, 2t =\frac{10t^4}{5}⇒f(t^2) = t$

put $t = 2/5, f(4/ 25) = 2/5$