若是 I = ∫ [x^2(sinx)^3/(x^4+2x^2+1)] dx,则 I = 0. 若是 I = ∫ {[x^2(sinx)^3/x^4]+2x^2+1} dx, 则 I = 0 + ∫ (2x^2+1)dx = 2∫ (2x^2+1)dx = 2[2x^3/3+x] = 530/3
