`A=[(cos theta, -sin theta),(sin theta, cos theta)]` and `AB=BA=l`, then `B` is equal to

If A = [(cos theta, sin theta),(-sin theta, cos theta)] and B = [(sin theta, - cos theta), (cos theta, sin theta)] , evaluate A cos theta + B sin theta .

Verify that [(cos theta, sin theta),(-sin theta, cos theta)] and [(cos theta, - sin theta),(sin theta, cos theta)] are inverse of each other.

If A=[[cos theta,sin theta-sin theta,cos theta]] and A(adjA)=lambda l then the value of lambda is and A(adjA)=lambda l

Prove that AB = BA when: A = {:[(cos theta, sin theta),(sintheta, costheta)] and B = [(cosphi, sin phi),(sinphi, cosphi)]

Evaluate the following determinants: (b) |(cos theta, -sin theta),(sin theta, cos theta)| = cos theta (cos theta) - sin theta(-sin theta) = cos^(2) theta + sin^(2) theta = 1

Area of a triangle whose vertices are (a cos theta, b sin theta) , ( - a sin theta , b cos theta) " and " ( - a cos theta, - b sin theta) is