If `2 costheta = x +1/x` and `2cosphi=y+1/y`, then

If 2costheta=a+1/a and 2 cosphi=b+1/b ,then prove that 2cos(theta-phi)=a/b+b/a

If cottheta+tantheta=x and sectheta-costheta=y then (i) sintheta costheta=-x (ii) sintheta tantheta=-y (iii) (x^2y)^(2/3)-(xy^2)^(2/3)=1 (iv) (x^2y)^(1/3)+(xy^2)^(1/3)=1

If 2costheta-sintheta=x and costheta-3sintheta=ydot Prove that 2x^2+y^2-2x y=5.

If cottheta+tantheta=x and sectheta-costheta=y then prove that (x^(2)y)^((2)/(3))-(xy^(2))^((2)/(3))=1

If cottheta+tantheta=x and sectheta-costheta=y , prove that (x^2y)^(2/3)-(x y^2)^(2/3)=1

If cottheta+tantheta=x and sectheta-costheta=y , prove that (x^2y)^(2/3)-(x y^2)^(2/3)=1

If cottheta+tantheta=x and sectheta-costheta=y , prove that (x^2y)^(2/3)-(x y^2)^(2/3)=1

If x/a costheta+y/b sintheta=1 and x/a sintheta-y/bcostheta=1 Prove that : (x^2)/(a^2)+(y^2)/(b^2)=2

If ((x)/(a) sin theta -(y)/(b) costheta )=1 and ((x)/(a)costheta +(y)/(b) sin theta)=1 , prove that ((x^(2))/(a^(2))+(y^(2))/(b^(2)))=2.

If:x/a costheta+y/b sin theta=1 and x/a sin theta-y/b cos theta=1, Prove that : (x^2)/(a^2)+(y^2)/(b^2)=2