`tan^(-1)x+tan^(-1)y=pi+tan^(-1)((x+y)/(1-xy))`

If x,y are real numbers such that xy<1 then tan^(-1)x+tan^(-1)y=tan^(-1)((x+y)/(1-xy))

The result tan^(-1)x-tan^(-1)y = tan^(-1)((x-y)/(1+xy)) is true when the value of xy is "………."

tan^(-1)x-tan^(-1)y=tan^(-1)((x-y)/(1+xy)) holds good for

Prove that : tan^(-1) x+cot^(-1) y = tan^(-1) ((xy+1)/(y-x))

Q.tan^(^^)-1x+tan^(^^)-1y=pi+tan^(^^)-1((x+y)/(1-xy)) if x,y>0 and xy>0Q*cos^(^^)-1x+cos^(^^)-1y=2pi-cos^(^^)-1(xy-sqrt(1-x^(^^)2)sqrt(1-y^(^^)2)) if x+y<0

tan^(-1)((x+y)/(1-xy)),xy<1 =

" (a) "tan^(-1)x+tan^(-1)y+tan^(-1)z=tan^(-1)(x+y+z-xyz)/(1-xy-yz-zx)

(v) Let x,y in R satisfying the equation tan^(-1)x+tan^(-1)y+tan^(-1)(xy)=(11 pi)/(12) ,then find the value of (dy)/(dx) at x=1 .

If tan^(-1)x+tan^(-1)y+tan^(-1)z=pi , then 1/(xy)+1/(yz)+1/(zx)=