dy=ln(x^2)·d(x^2)+x^2·dln(x^2)-sinxdx
=2x·ln(x^2)dx+x^2·1/x^2·d(x^2)-sinxdx
=2x·ln(x^2)dx+2xdx-sinxdx
=[2x·ln(x^2)+2x-sinx]dx
