Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

Find $\int \frac{2x}{\sqrt[3]{x^2 + 1}} dx$.

Options:

$\frac{2}{3} (x^2 + 1)^{3/2} + C$

$\frac{3}{2} (x^2 + 1)^{2/3} + C$

$3 (x^2 + 1)^{2/3} + C$

$\frac{3}{2} (x^2 + 1)^{1/3} + C$

Correct Answer:

$\frac{3}{2} (x^2 + 1)^{2/3} + C$

Explanation:

The correct answer is Option (2) → $\frac{3}{2} (x^2 + 1)^{2/3} + C$

$I=\int \frac{2x}{\sqrt[3]{x^2 + 1}} dx$

Let $x^2 + 1 = t$, then $2x dx = dt$.

$= \int \frac{dt}{t^{1/3}} = \int t^{-1/3} dt$

$= \frac{t^{2/3}}{2/3} + C = \frac{3}{2} t^{2/3} + C$

$= \frac{3(x^2 + 1)^{2/3}}{2} + C$