f(x)=sin(4分之派－x)分之cos2x化简

4个回答

f(x)=sin(4分之派－x)分之cos2x
=(cos^2x-sin^2x)/(根号2/2cosx-根号2/2sinx)
=(cosx+sinx)(cosx-sinx)/[(根号2/2)*(cosx-sinx)]
=根号2(cosx+sinx)
=2sin(x+Pai/4)