sinx+cosx=√2sin(x+0.25π)的证明过程
问题描述:
sinx+cosx=√2sin(x+0.25π)的证明过程
答
sinx+cosx
=根号2(根号2/2*sinx+根号2/2*cosx)
=根号2(sinxcosπ/4+sinπ/4cosx)
=√2sin(x+0.25π)