已知函数f(x)=(cos^2)x+2sinxcosx-(sin^2)x,求y=f(x)的最小正周期
问题描述：
已知函数f(x)=(cos^2)x+2sinxcosx-(sin^2)x,求y=f(x)的最小正周期
答
f(x)=(cos^2)x+2sinxcosx-(sin^2)x=(cos^2)x-(sin^2)x+2sinxcosx
=cos2x+sin2x
=√2(sin2x+π/4)
所以最小正周期T=2π/2=π