Prove that sin A/1+cos A = 1-cos A/sin A

Prove that (sin A)/(1 + cos A) + (sin A)/(1 - cos A) = 2 cosec A.

Prove that sin^2 A cos^2 B+cos^2 A sin^2 B+cos^2 A cos^2 B+sin^2 A sin^2 B=1

Prove that cos A cos 2A cos 2^(2) A cos 2^(3)A....cos 2^(n-1) A=(sin 2^(n) A)/(2^(n) sin A)

Prove that (sin 11 A sin A+sin 7A sin 3A)/(cos 11 A sin A+cos 7A sin 3A)=tan 8A

Expand cos ( A + B + C). Hence prove that cos A cos B cos C = sin A sin B cos C + sin B sin C cos A + sin C sin A cos B, if A + B + C = (pi)/(2) .

Prove that sin (A+B)= sin A cos B + cos A sin B.

Prove that ((cos^3A-sin^3A)/(cosA - sinA))- ((cos^3A + sin^3A)/(cosA + sinA))= 2sin A cos A

Prove that sin 4A=4 sin A cos^(3) A-4 cos A sin^(3) A

Prove that cos2A=cos^2 A -sin^2 A