If `cos^-1 (x/2)+cos^-1(y/3)=theta, then (x^2-12xycostheta+4y^2=` (A) 36 (B) `-36sin^2theta` (C) `36sin^2theta` (D) `36cos^2theta`

If cos^(-1)x/2+cos^(-1)y/3=theta , then 9x^2-12 x ycostheta+4y^2 is equal to (a) 36 (b) -36\ s in\ ^2theta (c) 36\ s in\ ^2theta (d) 36\ cos\ ^2theta

If cos^(-1)x/3+cos^(-1)y/2=theta/2 , then 4x^2-12 x ycostheta/2+9y^2= (a) 36 (b) 36-36costheta (c) 18-18costheta (d) 18+18costheta

If cos^(-1)x//2+cos^(-1) y//3=theta," prove that "9x^(2)-12xy cos theta+4y^(2)=36sin^(2) theta

If cos^(-1)((x)/(2))+cos^(-1)((y)/(3))=theta, prove that 9x^(2)-12xy cos theta+4y^(2)=36sin^(2)theta

If cos^(-1)x+cos^(-1)y=theta show that x^(2)-2xy cos theta+y^(2)=sin^(2)theta

If cos^(-1)((x)/(2))+cos^(-1)((y)/(3))=alpha then prove that 9x^(2)-12xy cos alpha+4y^(2)=36sin^(2)alpha

If : sin^(2) ((pi)/(4) + (theta)/(2)) - cos^(2) ((pi)/(4) + (theta)/(2))= A) sin theta B) cos theta C) sin 2 theta D) cos 2 theta