Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

$∫\frac{dx}{\sqrt{x+1}+(x+1)^{\frac{1}{3}}}$ is equal to

Options:

$2p^3-3P^2+6p-6ln(1+p)+c$, where $p=(x+1)^{\frac{1}{6}}$

$2p^3+6p-6ln(1+p)+c$, where $p=(x+1)^{\frac{1}{6}}$

$2p^3+3P^2+6p-6ln(1+p)+c$, where $p=(x+1)^{\frac{1}{6}}$

none of these

Correct Answer:

$2p^3-3P^2+6p-6ln(1+p)+c$, where $p=(x+1)^{\frac{1}{6}}$

Explanation:

Here $I=∫\frac{6p^5dp}{p^3+p^2}$  ((x + 1) = p6 , then dx = 6p5 dp).

$=6∫p^2dp-6∫p\,dp+6∫dp-6∫\frac{p^2}{p^2(p+1)}dp$

$=\frac{6p^3}{3}-\frac{6p^2}{2}+6p-6ln(p+1)+c$

$=2p^3-3P^2+6p-6ln(1+p)+c$, where $p=(x+1)^{\frac{1}{6}}$

Hence (A) is the correct answer.