Q80 / 150 · MHT CET 2022 (08 Aug Shift 1) · Mathematics
$\int_0^{\frac{\pi}{4}} \sec ^4 x d x=$
- A$\frac{2}{3}$
- B$\frac{1}{3}$
- Correct answerC$\frac{4}{3}$
- D1
Solution
$\begin{aligned} & \int_0^{\frac{\pi}{4}} \sec ^4 x \mathrm{~d} x=\int_0^{\frac{\pi}{4}}\left(\tan ^2 x+1\right) \sec ^2 x \mathrm{~d} x \\ & =\left[\frac{\tan ^3 x}{3}+\tan x\right]_0^{\frac{\pi}{4}} \\ & =\frac{1}{3}+1 \\ & =\frac{4}{3}\end{aligned}$
Hence, the correct answer is option: 'C'.