If Sec^-1(x/a)- Sec^-1(x/b)= Sec^-1 b- Sec^-1a then x=

Sin^-1(sin 2π/3) =

sin^-1(2cos² x-1)cos^-1(1-2sin² x)

4 Tan^-1 1/5- Tan^-1 1/70+Tan^-1 1/99 =

Tan (π/4+1/2cos^-1a/b) +tan (π/4-1/2cos^-1a/b) =

If 2Tan^-1(cos x) = Tan^-1(2 cosec x) then x=

Tan^-1 1/3+ Tan^-1 1/5+ Tan^-1 1/7+ Tan^-1 1/8 =

If Cosec^-1 x= 2Cot^-1 7+ Cos^-1(3/4) then the value of x is

IfTan^-1(1/7)= α, Tan^-1(1/3)=β then cos 2α =

Cos (sin^-13/5+Sin^-1 5/13)=