(1/48*(-30*x^4-45+90*x^2))*cos(2*x)+(1/48*(-12*x^5+60*x^3-90*x))*sin(2*x)+(1/12)*x^6+C
思路很简单,运算很麻烦.
用恒等式sin^2(x)=[1-cos(2x)]/2,逐次分部积分即可