`tan^-1(2/3)+tan^-1(4/5)=?`

Prove that: tan^-1 (1/3)+tan^-1 (2/9)+tan^-1 (4/33)+… tooo= pi/4

Prove that tan^-1(1/4)+ tan^-1(2/9) = 1/2sin^-1(4/5)

Prove that : tan^(-1)(1/2) + tan^(-1)(1/3) = tan^(-1)(3/5) + tan^(-1)(1/4) = pi/4

Prove that- tan^-1(1/2)+tan^-1(1/5)+tan^-1(1/8)=pi/4

tan^-1 (1/2) + tan^-1 (1/3) = π/4

Prove that tan ^(-1)(1/5) + tan^(-1)(1/7) +tan^(-1)(1/3)+ tan ^(-1)(1/8) = pi/4

Prove that tan^ (-1)( 1/3) +tan^(-1)( 1/5) + tan^(-1) (1/7 )+tan^(-1) (1/8) = pi/4

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

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

Prove that: tan^(-1)(1)/(7)+tan^(-1)(1)/(13)=tan^(-1)(2)/(9)tan^(-1)+tan^(-1)(1)/(5)+tan^(-1)(1)/(8)=(pi)/(4)tan^(-1)(3)/(4)+tan^(-1)(3)/(5)-tan^(-1)(8)/(19)=(pi)/(4)tan^(-1)(1)/(5)+tan^(-1)(1)/(7)+tan^(-1)(1)/(3)+tan^(-1)(1)/(8)=(pi)/(4)cot^(-1)7+cot^(-1)8+cot^(-1)18=cot^(-1)(1)/(13)