" 7.(i) "tan^(-1)x

(i) tan^(-1)sqrt(x) (ii) tan ^(-1)(2x+1)

(i) tan^(-1)sqrt(x) (ii) tan ^(-1)(2x+1)

Find the sum of each of the following series: (i) tan^(-1)((1)/(x^(2)+x+1))+tan^(-1)((1)/(x^(2)+3x+3))+tan^(-1)((1)/(x^(2)+5X+7))+tan^(-1)((1)/(x^(2))+7x+13))...... upto n.

Evaluate: (i) sin(tan^(-1)x+(tan^(-1)1)/(x)) for x>0( ii) cot(tan^(-1)a+cot^(-1)a)

Solve equation "tan"^(-1) 1/3 +"tan"^(-1) 1/5 +"tan"^(-1) 1/7 +"tan"^(-1)x=pi/4

If "tan"^(-1)(x+1)/(x-1)+"tan"^(-1)(x-1)/(x)=tan^(-1)(-7) then the value of x is

tan ^(-1) (1/3)+tan ^(-1) (1/5)+tan ^(-1) (1/7)=tan ^(-1) x, then x=

Solve, tan^(-1) (x+1)+tan^(-1) (x-1)=tan^(-1)""4/7

Find x if tan^(-1)(x) = tan^(-1)(1/2) + tan^(-1)(3/7)