为什么y=√3cosx+sinx=2sin(x+π/3)

问题描述:

为什么y=√3cosx+sinx=2sin(x+π/3)

y=SQR3cosx+sinx
=2(sqr3/2cosx+1/2sinx)
=2(sin60'cosx+cos60'sinx)
=2sin(x+60')
[60'=p/3]

其实就是证明积化和差公式。

y=2(√3/2cosx+1/2sinx)
=2(sinπ/3cosx+cosπ/3sinx)
=2sin(x+π/3)