∫0π/2sin2xcosx dx=\displaystyle\int_0^{\pi/2} \sin^2 x \cos x\,dx =∫0π/2sin2xcosxdx=A13\tfrac{1}{3}31check_circleB12\tfrac{1}{2}21C111Dπ/3\pi/3π/3Explanationu=sinxu = \sin xu=sinx, u(0)=0,u(π/2)=1u(0) = 0, u(\pi/2) = 1u(0)=0,u(π/2)=1. ∫01u2 du=1/3\int_0^1 u^2\,du = 1/3∫01u2du=1/3.