已知cos(π/6+α)=√3/3,则cos(5π/6-α)的值为 ( )

已知cos(π/6+α)=√3/3,则cos(5π/6-α)的值为 ( )
已知cos(π/6+α)=√3/3,则cos(5π/6-α)的值为 ( )

已知cos(π/6+α)=√3/3,则cos(5π/6-α)的值为 ( )
cos（5π/6-a)＝cos(a-5π/6）=cos(a+6/π-π）=负3分之根号3 很高兴为您回答题目.祝您天天好心情.