Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Indefinite Integration

Question:

Find the integral: $\displaystyle \int \frac{dx}{\sqrt{2x - x^2}}$

Options:

$\sin^{-1}(x - 1) + C$

$\cos^{-1}(x - 1) + C$

$\sin^{-1}(x + 1) + C$

$\log |x-1|\sin^{-1}(x + 1) + C$

Correct Answer:

$\sin^{-1}(x - 1) + C$

Explanation:

The correct answer is Option (1) → $\sin^{-1}(x - 1) + C$

$\int \frac{dx}{\sqrt{2x - x^2}} = \int \frac{dx}{\sqrt{1 - (x - 1)^2}}$

Put $x - 1 = t$. Then $dx = dt$.

Therefore, $\int \frac{dx}{\sqrt{2x - x^2}} = \int \frac{dt}{\sqrt{1 - t^2}} = \sin^{-1} (t) + C$

$= \sin^{-1} (x - 1) + C$