Mathematics · Definite Integration

JEE Advanced 2024 — Paper 2 — Question 39

Let f:[0,π2]→[0,1]f:\left[0, \frac{\pi}{2}\right] \rightarrow[0,1] be the function defined by f(x)=sin⁡2xf(x)=\sin ^{2} x and let g:[0,π2]→[0,∞)g:\left[0, \frac{\pi}{2}\right] \rightarrow[0, \infty) be the function defined by g=πx2−x2g=\sqrt{\frac{\pi x}{2}-x^{2}}.

The value of 16π3∫0π2f(x)g(x)dx\frac{16}{\pi^{3}} \int_{0}^{\frac{\pi}{2}} f(x) g(x) d x is \qquad

Answer: 0.25

Numerical answer — enter this value.

Step-by-step solution

I=16π3∫0π2f(x)g(x)dx=8π3∫0π2g(x)dx\quad I=\frac{16}{\pi^{3}} \int_{0}^{\frac{\pi}{2}} f(x) g(x) d x=\frac{8}{\pi^{3}} \int_{0}^{\frac{\pi}{2}} g(x) d x I=8π3∫0π2(π4)2−(π4−x)2dxI=\frac{8}{\pi^{3}} \int_{0}^{\frac{\pi}{2}} \sqrt{\left(\frac{\pi}{4}\right)^{2}-\left(\frac{\pi}{4}-x\right)^{2}} d x I=14\mathrm{I}=\frac{1}{4}

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Exam
JEE Advanced 2024
Paper
Paper 2
Subject
Mathematics
Chapter
Definite Integration
Topic
Evaluation of Definite Integrals