" 1."9x^(2)+12xy

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

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

The straight lines represented by the equation 9x^(2)-12xy+4y^(2)=0 are

The straight lines represented by the equation 9x^(2)-12xy+4y^(2)=0 are

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