" (viii) "sin^(4)A-cos^(4)A=2sin^(2)A-1=1-2cos^(2)A=sin^(2)A-cos^(2)A

sin^4A-cos^4A=2sin^2A-1=1-2cos^2A=sin^2A-cos^2A

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

cos^(4)A-sin^(4)A=2cos^(2)A-1

cos^(4)A-sin^(4)A=2cos^(2)A-1

sin^(4)x+cos^(4)x=1-2sin^(2)x cos^(2)x

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

Prove the following identities: (sin+cos A)/(sin A-cos A)+(sin-cos A)/(sin A+cos A)=(2)/(sin^(2)A-cos^(2)A)=(2)/(2sin^(2)A-1)=(2)/(1-2cos^(2)A)

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

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

Prove the following cos^(4)A-sin^(4)A+1=2cos^(2)A