tan(kπ+α)=?cos(kπ+α)=?
问题描述:
tan(kπ+α)=?cos(kπ+α)=?
答
tan(kπ+α)
=tanα
cos(kπ+α) =cosα ; if n=0,2,4,6,8...
=-cosα ; if n=1,3,5,...也就是说k=2n或2n+1?是