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`

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

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

Prove: sin^2Acos^2B-cos^2Asin^2B=sin^2A-sin^2B

Prove that cos^(4)A-sin^(4)A=cos^(2)A-sin^(2)A .

Prove that : cos^(4) A - sin^(4) A = 2 cos^(2) A - 1

Prove that: sin2x+2sin4x+sin6x=4cos^2xsin4

Prove that : 2 sin^(2) A + cos^(4) A = 1 + sin^(4) A

Prove that in a A B C ,sin^2A+sin^2B+sin^2C<=9/4dot

If A+B+C=pi and A+B=2C , prove that : 4 (sin^2 A + sin^2 B - sinA sinB)=3 .

Prove that sin2A + sin2B + sin2C = 4sinA · sinB · sin C