Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Indefinite Integration

Question:

The value of the integral $I=∫\frac{(logx)^3}{x}dx $ is :

Options:

$\frac{1}{4}log(x^4)+C,$ where C is a constant

$\frac{(logx)^4}{4}+C,$ where C is a constant

$\frac{1}{2}log(x^2)+C,$ where C is a constant

$\frac{1}{2}(logx)^4+C,$ where C is a constant

Correct Answer:

$\frac{(logx)^4}{4}+C,$ where C is a constant

Explanation:

The correct answer is Option (2) → $\frac{(logx)^4}{4}+C,$ where C is a constant

$I=\int\frac{(\log x)^3}{x}dx$

Let $y=\log x$, $dy=\frac{dx}{x}$

$⇒I=\int y^3dy$

$⇒\frac{y^4}{4}+C=\frac{(\log x)^4}{4}+C$