If `cos^(-1)(x)/(2)+cos^(-1)(y)/(3)=theta` then the maximum of `9x^(2)-12xy costheta + 4y^(2)` is

If cos^(-1)((x)/(3))+cos^(-1)((y)/(2))=(theta)/(2) , then the value of 4x^(2)-12xy cos((theta)/(2))+9y^(2) is equal to :

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

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/m)+cos^(-1)(y/n)=theta , then x^2/m^2-(2xy)/(mn)costheta+y^2/n^2 is equal to

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

cos^(-1)x-cos^(-1)(y/2)=alpha,x in[-1,1],y in[-2,2] then the value of 4x^(2)-4xy cos alpha+y^(2) is

If cos ^(-1) .(x)/(a)+ cos ^(-1). (y)/(b) = theta then prove that (x^(2))/(a^(2)) -(2xy)/(ab) . cos theta+ (y^(2))/(b^(2)) = sin ^(2) theta .