[" 12."cos thetaquad cos theta],[" 12.(a) "(sin theta+cos theta)^(2)+(sin theta-cos theta)^(2)=2]

((sin theta+cos theta)^(2)-1)/(sin theta*cos theta)

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

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

If tan theta=5/6 then (12 sin theta-5cos theta)/(12sin theta+5cos theta)=

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

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))

Prove that (sin theta+cos theta)/(sin theta- cos theta) + (sin theta - cos theta)/(sin theta + cos theta) = ( 2sec^(2) theta)/(tan^(2) theta -1) .

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

cos theta+sin theta=cos2 theta+sin2 theta

If 5 cos theta = 6 , sin theta , evalutate : (12 sin theta - 3cos theta)/(12 sin theta + 3 cos theta)