链式法则dy=d[f(sin²x)+f(cos²x)]=d (f(sin²x))+d(f(cos²x))=f'(sin^2 x)*d(sin^2 x)+f'(cos^2 x)*d(cos^2 x)=[f'(sin^2 x)*2sinxcosx+f'(cos^2 x)*2cosx(-sinx)]dx=sin2x *[f'(sin²x)-f'(...