Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

Given $p \neq 1$, then $\int \frac{\mathrm{d} x}{x\left(\log _{e} x\right)^{p}}$ is equal to :

Options:

$\frac{\left(\log _{e} x\right)^{1+p}}{1+p}$

$\frac{1+p}{\left(\log _{e} x\right)^{1+p}}$

$\frac{\left(\log _{e} x\right)^{1-p}}{1-p}$

$\frac{1-p}{\left(\log _e x\right)^{1-p}}$

Correct Answer:

$\frac{\left(\log _{e} x\right)^{1-p}}{1-p}$

Explanation:

p ≠ 1 , then  $I = \int \frac{dx}{x(log ~ x)^p}$

let y = log x

dy = $\frac{1}{x}$ dx

$\Rightarrow I =\int \frac{1}{y^p} d y$

$=\frac{y^{-p+1}}{-p+1} ≡ \frac{y^{1-p}}{1-p}$

$\Rightarrow I=\frac{(\log x)^{1-p}}{1-p}$