Prove that `(3 + cos 4theta) cos 2theta = 4(cos^(8)theta - sin^(8)theta)`.

(3+cos4 theta)cos2 theta=4(cos^(8)theta-sin^(8)theta)

Prove that : cos^(4)theta - cos^(2)theta = sin^(4)theta - sin^(2) theta

Prove that (cos^(4)theta-sin^(4)theta)/(cos^(2)theta-sin^(2)theta)=1

Prove that: (sin theta - 2 sin^(3) theta) = (2cos^(3) theta - cos theta) tan theta .

Prove that : (2 cos^(3) theta-cos theta)/(sin theta-2 sin^(3)theta)=cot theta

1-8 cos ^(2) theta + 8 cos ^(4) theta= A) sin 4 theta B) cos 4 theta C) sin ^(4) theta + cos ^(4) theta D) sin ^(4) theta - cos ^(4) theta

Prove each of the following identities : (cos^(3) theta + sin^(3) theta)/(cos theta + sin theta ) + (cos^(3) theta - sin^(3) theta)/(cos theta - sin theta ) = 2

Prove that sin theta cos^(3)theta - cos theta sin^(3) theta = (1)/(4) sin 4 theta .

Prove that : sin^(2)theta+cos^(4)theta=cos^(2)theta+sin^(4)theta

The value of 3(cos theta-sin theta)^(4)+6(sin theta+cos theta)^(2)+4 sin^(6) theta is where theta in ((pi)/(4),(pi)/(2)) (a) 13-4cos^(4) theta (b) 13-4cos^(6) theta (c) 13-4cos^(6) theta+ 2 sin^(4) theta cos^(2) theta (d) 13-4cos^(4) theta+ 2 sin^(4) theta cos^(2) theta