(ii) Prove `cos x cos (60 -x) cos(60+x) = 1/4 cos 3x`

Prove that :cos A cos(60-A)cos(60+A)=(1)/(4)cos3A

Prove that: (i) cos A cos(60^(@)-A)cos (60^(@)+A)=(1)/(4)cos 3A (ii) "tan" A+"tan"(60^(@)+A)-"tan"(60^(@)-A)=3 tan 3A .

1+ cos 2x+ cos4x + cos 6x=

cos 10x + cos 8x + 3 cos 4x + 3 cos 2x=

Prove that 1 + cos 2x + cos 4x + cos 6x = 4 cos x *cos 2x *cos 3x .

Prove that: cosA. Cos(60^(@)+A)cos(60^(2)-A)=1/4 cos3A

Prove that: cos A cos(60^(@)-A)cos(60^(@)+A)=(1)/(4)cos3A

Prove that (cos x + sin x)/(cos x - sin x) - (cos x - sin x)/(cos x + sin x) = 2 tan x

Prove that: 1+cos2x+cos4x+cos6x=4cos x cos2x cos3x