Evaluate :

`-cos^(2)( theta ) - sin^(2)( theta )`

Evaluate : ( Cos^2theta - Sin^2theta ) / ( ( Costheta - Sintheta )^2

Evaluate : ( Cos^2theta - Sin^2theta ) / ( ( Costheta - Sintheta )^2

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

Evaluate 2(cos^2theta-sin^2theta)=1

If tan theta=(12)/(13), evaluate (2sin theta cos theta)/(cos^(2)theta-sin^(2)theta)

Evaluate: int cos2 theta ln((cos theta+sin theta)/(cos theta-sin theta))d theta

Evaluate sin theta.cos theta , if sin theta + cos theta= sqrt2 .

Find the maximum and minimum value of cos^(2) theta- 6 sin theta cos theta + 3 sin^(2) theta + 2 .