`2 tan ^(-1) ""(1)/(2) = tan^(-1) ""(4) /(3) `

tan^(-1) 1+tan ^(-1) 2+tan ^(-1) 3 = pi =2 (tan ^(-1) ""(1)/(2)+tan ^(-1) ""(1)/(3) + tan ^(-1) 1) [ take priencipal value in each case]

tan ^(-1) "" (1)/(2) + tan ^(-1) "" (2)/(11) = tan ^(-1)""(3)/(4)

Show that tan^(-1)""(1)/(2) + tan^(-1)""(2)/( 11) + tan^(-1)""(4)/(3) = (pi)/(2)

Prove that tan^(-1)""(1)/(4)+tan^(-1)""(2)/(9)=(1)/(2)tan^(-1)""(4)/(3)

3tan ^(-1) ""(1)/(2+sqrt(3))-tan ^(-1)""(1)/(2)=tan^(-1 )""(1)/(3)

Prove that 2tan^(-1)((1)/(2))=tan^(-1)((4)/(3))

tan ^ (- 1) ((1) / (4)) + tan ^ (- 1) ((2) / (9)) = (1) / (2) tan ^ (- 1) ((4) / (3))

Prove that "tan"^(-1)(1)/(4) +"tan"^(-1)(2)/(9) =(1)/(2)"tan"^(-1)(4)/(3) .

tan^-1 (1/2) + tan^-1 (1/3) = π/4