" (ii) "cos^(2)(theta+phi)-sin^(2)(theta-phi)=cos2 theta cos2 theta

Prove that, cos^(2) (theta + phi) - sin^(2) (theta - phi) = cos 2 theta cos 2 phi

Prove that: cos2 theta*cos2 phi+cos^(2)(theta+phi)-cos^(2)(theta-phi)=cos(2 theta+2 phi)

cos2 theta cos2 phi+sin^(2)(theta-phi)-sin^(2)(theta+phi)=cos(2 theta+2 phi)

Prove that cos 2 theta cos 2 phi + sin ^(2) ( theta - phi) -sin ^(2) (theta + phi) = cos ( 2 theta + 2 phi).

The value of the determinant ,cos(theta+phi),-sin(theta+phi),cos2 phisin theta,cos theta,sin phi-cos theta,sin theta,cos phi]| is

"cos"2theta."cos"2phi+"sin"^(2)(theta-phi)-"sin"^(2)(theta+phi) is equal to (i) "sin"2(theta+phi) (ii) "cos"2(theta+phi) (iii) "sin"2(theta-phi) (iv) "cos"2(theta-phi)

if determinant |{:( cos (theta + phi),,-sin (theta+phi),,cos 2phi),(sin theta,,cos theta,,sin phi),(-cos theta,,sintheta,,cos phi):}| is

if determinant |{:( cos (theta + phi),,-sin (theta+phi),,cos 2phi),(sin theta,,cos theta,,sin phi),(-cos theta,,sintheta,,cos phi):}| is

if determinant |{:( cos (theta + phi),,-sin (theta+phi),,cos 2phi),(sin theta,,cos theta,,sin phi),(-cos theta,,sintheta,,cos phi):}| is

cos2thetacos2phi+sin^2(theta-phi)-sin^2(theta+phi)=