[" (ch) यदि "cos^(-1)(x)/(a)+cos^(-1)(y)/(b)=0," तो सिद्ध कीजिए कि "],[qquad (x^(2))/(a^(2))-(2xy)/(ab)cos theta+(y^(2))/(b^(2))=sin^(2)theta]

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 .

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 .

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 .

if cos ^(-1 ) ""(x )/(a) + cos ^(-1 )""(y)/(b ) = alpha prove that , (x^(2) )/(a^(2)) -(2xy)/(ab ) ""cos alpha +(y^(2))/(b^(2))= sin ^(2) alpha

cos^(-1)(x//a)+cos^(-1)(y//b)=theta ,then (x^(2))/(a^(2))-(2xy)/(ab)cos theta+(y^(2))/(b^(2))=

If cos^(-1)(x/a) + cos^(-1) (y/b) = a show that : (x^2)/(a^2) - (2xy)/(ab) cos alpha + (y^2)/(b^2) = sin^(2) alpha .

If cos^(-1)""x/a+cos^(-1)""y/b=theta , Prove that x^(2)/a^(2)-(2xy)/(ab)costheta+y^(2)/b^(2)=sin^(2)theta .