((2cos (60 - a) - cos a) / (√ 3 SIN a)) +8 cos ^2 (60)

Question

((2cos (60 - a) - cos a) / (√ 3 SIN a)) +8 cos ^2 (60)

Answer 1

2cos(60-a)-cosa=2*cos60*sina+2*sin60*sina-cosa=
=2*1/2*cosa+2*√3/2*sina-cosa=cosa+√3sina-cosa=√3sina
√3sina:√3sina=1
1+8cos²60=1+8*1/4=1+2=3