y=根号(cosx^2-cosx^4)的最小正周期是
问题描述：
y=根号(cosx^2-cosx^4)的最小正周期是
答
y=√(cosx^2-cosx^4)
=√[cosx^2(1-cosx^2)]
=√[cosx^2*sinx^2)]
=√[4cosx^2*sinx^2)/4]
=√[(sin2x^2)/4]
=∣sin2x∣/2
T=2π/2=π