The value of Cot [Cot^-1 7+ Cot^-1 8+ Cot^-1 (18)] is

The number of real solutions of Tan¹ x+Tan ¹ (1/y) = Tan¹ 3 is

Cot^-1(4/3)-Cos^-1(15/8) =

The equation Sin^-1 x- Cos^-1 x=Cos^-1 (√3/2) has

4 Tan^-1 1/5- Tan^-1 1/239 =

The domain of Cosh^-1 3x is

The ascending order of A= Sin^-1(sin 8π/7),B= Cos^-1(cos 8π/7), ), C=Tan^-1(tan 8π/7) is

Cos^-1(63/65) + 2 Tan^-1(1/5) =

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

Let Then which one of the following is true