Prove that `cos 5A = 16 cos^5A - 20 Cos^3 A + 5 cos A`

Prove that: cos5A=16cos^5A-20cos^3A+5cosA

Prove that 16 cos ^(5) theta - 20 cos ^(3) theta + 5 cos theta = cos 5 theta.

Prove that (cos 3A +2 cos 5 A + cos 7A)/( cos A + 2 cos 3 A + cos 5A) = cos 2 A - sin 2 A tan 3 A.

Prove that: cos 100^0+cos 20^0=cos 40^0

Prove that: (cos2A\ cos3A-cos2Acos7A+cos10 A cos A)/(sin4A\ sin3A-sin2A sin5A+sin4Asin7A )=cot6A\ cot5A

Prove that 2cosx. Cos 3x- 2cos 5x. Cos 7x- cos 4x + cos12x=0 .

Prove that: cos3A+cos5A+cos7A+cos 15 A=4cos4A cos5A cos6A

Prove that (sin 7A - sin 5A)/(cos 5 A + cos 7A ) = tan A.

Prove that: (cos3A+2cos5A+cos7A)/(cos A+2cos3A+cos5A)=(cos5A)/(cos3A)

Prove that: \ cos A+cos3A+cos5A+cos7A=4cos A cos2A cos4A