`cos^(4)(A/2)-sin^(4)(A/2)=cos A`

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

What is ( cos ^(4) A - sin ^(4) A)/( cos ^(2) A - sin ^(2) A) equal to ?

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

If A+B-C=3pi, t h e n sin A+ sin B-sin C is equal to- a.4sin(A/2)sin(B/2)cos(C/2) b. -4sin(A/2)sin(B/2)cos(C/2) c. 4cos(A/2)cos(B/2)cos(C/2) d. -4cos(A/2)cos(B/2)cos(C/2)

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

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

(cos2 alpha)/(cos^(4)alpha-sin^(4)alpha)-(cos^(4)alpha+sin^(4)alpha)/(2-sin^(2)2 alpha)=