Prove that
i) `tan^(-1)(1+x)/(1-x)=pi/4 + tan^(-1)x,x lt 1`
ii) `tan^(-1)x+cot^(-1)(x+1)=tan^(-1)(x^(2)+x+1)`

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

tan^(-1)(cot x)+cot^(-1)(tan x)

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

tan^(-1)(cot x)-tan^(-1)(cot2x)=

Prove that tan(cot^(-1)x)=cot(tan^(-1)x)

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

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

" (i) "tan^(-1)x+cot^(-1)((1+x)/(1-x))=(pi)/(4)

prove that tan^(-1)x+cot^(-1)x=pi/2

Prove that: i) sin^(-1)(3x-4x^(3))=3sin^(-1)x, |x| le 1/2 ii) cos^(-1)(4x^(2)-3x)=3cos^(-1)x,1/2 le x le 1 iii) tan^(-1)""(3x-x^(3))/(1-3x^(2))=3tan^(-1)x, |x| lt 1/sqrt(3) iv) tan^(-1)x+tan^(-1)""(2x)/(1-x^(2))=tan^(-1)""(3x-x^(3))/(1-3x^(2))