A. 2+2cos 2θ-2cos 4θ-cos 6θ
B. 2-2cos 2θ-2cos 4θ-cos 6θ
C. 2+2cos 2θ+2cos 4θ-cos 6θ
D. 2+2cos 2θ+2cos 4θ+cos 6θ
27 cos8 θ=
128 sin8 θ=
27 cos5 θsin3 θ=
The last terms in the expantions of sin 8θ, sin 9θ respectively are
If cos α+ cos β=0= sin α + sin β then cos(α - β)=
If 16 sin5 θ=asin 5 θ+b sin 3θ+c sin θ then
64cos3 θsin4 θ=