`cos^4A -cos^2A= Sin^4A- Sin^2A`

If (cos^4A)/(cos^2B)+(sin^4A)/(sin^2B)=1 then prove that (cos^4B)/(cos^2A)+(sin^4B)/(sin^2A)=1

If (cos^4A)/(cos^2B)+(sin^4A)/(sin^2B)=1 , then prove that (i) sin^4A+sin^4B=2 sin^2Asin^2B (ii) (cos^4B)/(cos^2A)+(sin^4B)/(sin^2A)=1

Prove that: cos^2 2x-cos^2 6x= sin4x sin8x

Prove the following identities: sin^4A-cos^4A=sin^2A-cos^2A=2sin^2A-1=1-2cos^2A

Prove that: (sin3A cos4A-sin Acos2A)/(sin4A sin A+cos6A cos A)=tan2A

If cosA+cos^2A=1 , then sin^2A+sin^4A=

If (cos^4 A)/(cos^2 B) + (sin^4 A)/(sin^2 B) =1 , Prove that: sin^4 A+sin^4 B=2 sin^2 A sin^2 B

Prove that: Sin 4A = 4 cos^3 A sin A - 4 sin^3 A cos A

Prove that: (cos4A+cos3A+cos2A)/(sin4A+sin3A+sin2A)=cot3A

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