y=x *e^(-x)*sin(x/2)那么求微分得到dy=x' *e^(-x)*sin(x/2)+x *[e^(-x)]' *sin(x/2)+x *e^(-x)*[sin(x/2)]'=[e^(-x)*sin(x/2) -x *e^(-x) *sin(x/2)+x/ *e^(-x)* cos(x/2)]dx而y=ln[x/√(1-x^2)]=lnx -1/2 ln(1-x^2)求微分得到dy=[1/x+x/(1-x^2)] dx