cos25π/3等于?请告诉我具体的方法,O(∩_∩)O谢谢

问题描述:

cos25π/3等于?请告诉我具体的方法,O(∩_∩)O谢谢

cos25π/3
=cos(24π/3+π/3)
=cos(8π+π/3) (周期是2π)
=cos(π/3))
=1/2