已知函数f(x)=2sinxcosx+cos2x

问题描述:

已知函数f(x)=2sinxcosx+cos2x
1求f(π/4)的值
2设α属于(0,π),f(α/2)=根号2/2,求sinα

f(x)=sin2x+cos2x=√2sin(2x+π/4)
f(π/4)=√2sin(2*π/4+π/4)=√2*√2/2=1
0