Formula for `2tan^-1x` and `3tan^-1x`

Formula for 2tan^(-1)x and 3tan^(-1)x

Formula for tan^(-1)(x)+-tan^(-1)(y)

Solve for x, tan^(-1)(x-1)+tan^(-1)x +tan^(-1)(x+1) =tan^(-1)3x .

Prove that tan (2 tan^(-1) x ) = 2 tan (tan^(-1) x + tan^(-1) x^(3)) .

Prove that tan (2 tan^(-1) x ) = 2 tan (tan^(-1) x + tan^(-1) x^(3)) .

Solve for x : tan^(-1)(2+x)+tan^(-1)(2-x)=tan^(-1)2/3 , where x sqrt(3)

If tan^-1 x + tan^-1 2x + tan^-1 3x = pi , then:

Prove that tan(2tan^(-1)x)=2tan(tan^(-1)x+tan^(-1)x^(3))

Let |{:(tan^(-1)x, tan^(-1)2x, tan^(-1)3x), (tan^(-1)3x, tan^(-1)x, tan^(-1)2x), (tan^(-1)2x, tan^(-1)3x, tan^(-1)x):}|=0 , then the number of values of x satisfying the equation is

Solve for x , tan^(-1) ( x + 1) + tan^(-1) x + tan^(-1) ( x - 1) = tan ^(-1) 3