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

1.	Prove that `tan^(-1) x + cot^(-1) (x+1) = tan ^(-1) (x^(2) + x+1)`.
Answer» L.H.S =` tan^(-1).(1)/(4) + tan^(-1) .(2)/(9)` `= tan^(-1).((1)/(4)+(2)/(9))/(1-(1)/(4) xx(2)/(9))` `= tan^(-1).(x+(1)/(x+1))/(1-x.(1)/(x+1))= tan ^(-1).(x(x-1)+1)/((x+ 1)-x)` `tan^(-1) (x^(2) + x+1)` = R.H.S

Discussion

If `sin ^(-1) .(2a)/(1+a^(2))+ coses^(2) (cot ^(-1) 3) y =?`A. `(a+b)/(1-ab)`B. `(a+b)/(1+ab)`C. `(a-b)/(1+ab)`D. None of these
Prove that:`tan^(-1)1/5+tan^(-1)1/7+tan^(-1)1/3+tan^(-1)1/8=pi/4`
`If"sin"{cot^(-1)(x+1)}="cos"(tan^(-1)x),`then find `xdot`A. `sqrt((x^(2)+2)/(x^(2)+1))`B. `(x)/sqrt(x^(2)+1)`C. `(x)/sqrt(x^(2)+2)`D. `sqrt((x^(2) +1)/(x^(2) + 2))`
If `(tan^(-1)x)^2+(cot^(-1)x)^2=(5pi^2)/8,`then find `xdot`A. 1B. -1C. `(1)/sqrt(3)`D. `-(1)/sqrt(3)`
The Principal value of `os^(-1) (sqrt(3)/(2))` is :A. `(pi)/(8)`B. `(pi)/(6)`C. `(pi)/(3)`D. None of these
If `sin(sin^(-1)1/5+cos^(-1)x)=1,`then find the value of `xdot`
`sec^(2) (tan^(-1) 4) + cosec^(2) (cot ^(-1) 3) =?`A. 30B. 29C. 27D. 25
`tan^(-1)sqrt(3)-cot^(-1)(-sqrt(3))`is equal to(A) `pi` (B) `-pi/2` (C) 0 (D) `2sqrt(3)`A. `pi`B. `-(pi)/(2)`C. `0`D. `2sqrt(3)`
Prove that:`sin^(-1)8/(17)+sin^(-1)3/5=tan^(-1)(77)/(36)`
Find the value of: `tan1/2[sin^(-1)(2x)/(1+x^2)+cos^(-1)(1-y^2)/(1+y^2)],|x|0`and `x y" "