函数y=2根号下3sinxcosx-cos^2+sin^2的图像在(0,m)上恰好有两个点的纵坐标为1,则
问题描述:
函数y=2根号下3sinxcosx-cos^2+sin^2的图像在(0,m)上恰好有两个点的纵坐标为1,则
答
y=2根号下3sinxcosx-cos^2+sin^2
=√3sin2x-cos2x
=2sin(2x-π/6)
解2sin(2x-π/6)=1得,2x-π/6=2kπ+π/6或2kπ+5π/6,∴x=kπ+π/6或kπ+π/2
∴取k=0,x=π/6,π/2;取k=1,x=7π/6,3π/2
∴π/2