MCQ
$\int_0^\pi {{{\sin }^2}x\,dx} $ is equal to
  • A
    $\pi $
  • $\frac{\pi }{2}$
  • C
    $0$
  • D
    None of these

Answer

Correct option: B.
$\frac{\pi }{2}$
b
(b) $I = \int_0^\pi {{{\sin }^2}x\,dx = 2\int_0^{\pi /2} {{{\sin }^2}x\,dx} } $,

$\{\because \,\,\int_{0}^{2a}{f(x)=2\int_{0}^{a}{f(a-x)dx}}$, if $f(2a - x) = f(x) \}$

$I = 2 \times \frac{1}{2} \times \frac{\pi }{2} = \frac{\pi }{2}$.

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