`(x^(-1))/(x^(-1)+y^(-1))+(x^(-1))/(x^(-1)-y^(-1))` is equal to

What is the expression (x+y)^(-1) (x^(-1) +y^(-1)) (xy^(-1) +x^(-1)y)^(-1) equal to:

(x/y)^(-1)=(x)^(-1)/(y)^(-1)

Tan^(-1)((x)/(y))-Tan^(-1)((x-y)/(x+y)) is equal to

If y=sec^(-1)((x+1)/(x-1))+sin^(-1)((x-1)/(x+1)) then (dy)/(dx) is equal to :

(x^(-1)-y^(-1))/(z)+(y^(-1)-z^(-1))/(x)+(z^(-1)-x^(-1))/(y)= _______

The solution of (dy)/(dx)=((x-1)^(2)+(y-2)^(2)tan^(-1)((y-2)/(x-1)))/((xy-2x-y+2)tan^(-1)((y-2)/(x-1))) is equal to

Prove that ((x^(-1)+y^(-1))/x^(-1))^(-1)+((x^(-1)-y^(-1))/x^(-1))^(-1)=(2y^(2))/(y^(2)-x^(2))

If y^((1)/(n))+y^(-(1)/(n))=2x then (x^(2)-1)y_(2)+xy_(1) is equal to

If sin^(-1)x+sin^(-1)y=(2pi)/3 , then cos^(-1)x+cos^(-1)y is equal to