Solve `cos^(2)theta-sin^(2)theta=1-2cos^(2)theta`

Solve cos^(4)theta-sin^(4)theta=cos^2theta

Solve cos^(2)theta+sin theta=1

Prove the following 1.((1-cos^(2)theta)/(sin^(2)theta))=12.1-((cos^(2)theta)/(1+sin theta))=sin theta

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

Prove the following identities: 2(sin^(6)theta+cos^(6)theta)-3(sin^(4)theta+cos^(4)theta)+1=0sin^(6)theta+cos^(6)theta+3sin^(2)theta cos^(2)theta=1(sin^(8)theta-cos^(8)theta)=(sin^(2)theta-cos^(2)theta)(1-2sin^(2)theta cos^(2)theta)

Solve: cos2theta=cos^(2)theta

If : sin^(4)theta+cos^(4)theta+sin^(2)theta*cos^(2)theta=1-u^(2), "then" : u=

If cos theta+cos^(2)theta=1 then sin^(2)theta+2sin^(2)theta+sin^(2)theta=

Prove the following identity: ((1)/(sec^(2)theta-cos^(2)theta)+(1)/(cos ec^(2)theta-sin^(2)theta))sin^(2)theta cos^(2)theta=(1-sin^(2)theta cos^(2)theta)/(2+sin^(2)cos^(2)theta)