∫xf﹙x²﹚f'﹙x²﹚dx=怎么解
问题描述：
∫xf﹙x²﹚f'﹙x²﹚dx=
怎么解
答
∫xf﹙x²﹚f'﹙x²﹚dx=(1/2)∫f﹙x²﹚f'﹙x²﹚d(x^2)=(1/2)∫f﹙x²﹚df(x^2)
=[f﹙x²﹚]^2/4