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