若sin(π/6-a)=根号3/3,则sin(7π/6-a)=

问题描述:

若sin(π/6-a)=根号3/3,则sin(7π/6-a)=

sin(7π/6-a)
=sin(π+π/6-a)
=-sin(π/6-a)
=-根号3/3