$\int_0^1 \sqrt{\frac{1-x}{1+x}} d x=$

$\int_0^1 \sqrt{\frac{1-x}{1+x}} d x=$
  1. $\frac{\pi}{4}+1$
  2. $\frac{\pi}{2}+1$
  3. $\frac{\pi}{4}-1$
  4. $\frac{\pi}{2}-1$

Solution

$\begin{aligned} & \int_0^1 \sqrt{\frac{1-x}{1+x}} d x=\int_0^1 \frac{1-x}{\sqrt{1-x^2}} d x=\int_0^1 \frac{1}{\sqrt{1-x^2}} d x+\frac{1}{2} \int_0^1 \frac{-2 x}{\sqrt{1-x^2}} d x \\ & =\left[\sin ^{-1} x\right]_0^1+\left[\sqrt{1-x^2}\right]_0^1 \\ & =\sin ^{-1}(1)-\sin ^{-1}(0)+\sqrt{1-1^2}-\sqrt{1-0^2} \\ & =\frac{\pi}{2}-0+0-1 \\ & =\frac{\pi}{2}-1\end{aligned}$

Asked in: MHT CET 2022 (07 Aug Shift 2)

Practice more Definite Integration questions on Aicharya