" ชì "y=(tan^(-1)x)^(2)" ¿ilu,"fl" ? "

cos ^(-1) ""((cos x + cos y)/(1+cos x cos y))= 2 tan ^(-1) (tan ""(x)/(2) tan ""(y)/(2))

If tan ^(-1) x+tan ^(-1) y+tan ^(-1) z=(pi)/(2), then 1-x y-y z-z x=

If y = tan^(-1) ((1)/(1 + x + x^(2))) + tan^(-1) ((1) /(x^(2) + 2x + 3)) + tan^(-1) ((1)/(x^(2) + 5x + 7)) + ….n terms , then y(0) is

If cos ^ (- 1) x + cos ^ (- 1) y = (pi) / (2), tan ^ (- 1) x-tan ^ (- 1) y = 0 then x ^ (2) + xy + y ^ (2) =

If xy=1 + a^(2) then show that tan^(-1) ""(1)/(a+x)+tan ^(-1) ""(1)/(a+y)=tan ^(-1)""(1)/(a) , x+y+2a ne 0

If xy =1 +a^(2) , show that tan ^(-1) ""(1)/(a+x) +tan^-1"" 1/(a+y) = tan ^(-1) ""(1)/(a) , ( x+ y + 2a) ne 0

If tan ^(-1) x+tan ^(-1) y+tan ^(-1) z=(pi)/(2) then x y+y z+z x=

If tan ^(-1) ""x + tan ^(-1) ""y + tan ^(-1) ""z=(pi)/(2) and x + y +z = sqrt(3) then show that x =y=z.

Prove the "tan"^(-1) 1/(x+y) + "tan"^(-1) y/(x^2=xy+1) ="tan"^(-1)1/x