If `x cos theta + y sin theta =2` is perpendicular to the line x-y =3 then what is one of the value of `theta`?

If x cos theta + y sin theta =2 and x cos theta - y sin theta =0 , then which one of the following is true ?

Find the equation of the straight line through (a cos theta, b sin theta) perpendicular to the line x/(a cos theta)+ y/(b sin theta) = 1 .

The equation to the straight line passing through the point (a "cos"^(3) theta, a "sin"^(3) theta) and perpendicular to the line x "sec" theta + y"cosec" theta = a is

The equation to the straight line passing through the point (a cos^(3)theta,a sin^(3)theta) and perpendicular to the line x sec theta+y csc theta=a is x cos theta-y sin theta=a cos2 thetax cos theta+y sin theta=a cos2 thetax sin theta+y cos theta=a cos2 theta none of these

If x=a cos theta - b sin theta , and y=a sin theta+b cos theta , what is the value of (x^2+y^2)/(a^2+b^2) ?

If x sin^(3) theta + y cos^(3) theta = sin theta cos theta and x sin theta = y cos theta , then the value of x^(2) + y^(2) is :