Tan^-1(cot x) - Tan^-1(cot 2x)=

If Sin^-1 x+ Sin^-1 y+ Sin^-1 z=π then x²+y²+z²+2xyz=

If Tan^-1 x+ Tan^-1 y+ Tan^-1 z=π, then x+y+z=

Sin^-1 (16/65) +2 Tan^-1 (1/5) =

If Cot^-1 4/3+Cot^-1 5/3= Tan^-1 k, then k=

2 Tan^-1 1/3+Tan^-1 1/7=

Sin (2Tan^-13/4) =

Tan^-1 3/2-Tan^-11/5 =

If tan^-1 2, tan^-13 are two angles of a triangle, then the third angle is

Two angles ofa triangle are Cot^-1 2 and Cot^-1 3.Then the third angle is