Sin 24*cos 6-cos 84*sin66/sin 21*cos39-sin69*cos51

Question

Sin 24*cos 6-cos 84*sin66/sin 21*cos39-sin69*cos51

Answer 1

(sin24cos6-sin6cos24)/(sin21cos39-cos21sin39)=sin(24-6)/sin(21-39)=
=sin18/sin(-18)=sin18/(-sin18)=-1