Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

$\int\frac{(2x^2+3)dx}{(x^2-1)(x^2+4)}=k\log(\frac{x+1}{x-1})+k(\tan^{-1}(\frac{x}{2}))$, then k equals:

Options:

log 2

1/2

1/3

$\frac{1}{\log 2}$

Correct Answer:

1/2

Explanation:

$\int\frac{2x^2+3dx}{(x^2-1)(x^2+4)}=\int\frac{1}{x^2-1}+\frac{1}{x^2+4}dx$

$=\frac{1}{2}\log\left|\frac{x+1}{x-1}\right|+\frac{1}{2}\tan^{-1}\frac{x}{2}+C$

$⇒k=\frac{1}{2}$ On comparison