Find: `cot^-1(1)+cot^-1(1/2)+cot^-1(1/3)`

If S_n=cot^-1(3)+cot^-1(7)+cot^-1(13)+cot^-1(21)+..... , n terms, then

Prove that cot^(-1)(13)+cot^(-1)(21)+cot^(-1)(-8)=pi .

If A = 1/1 cot ^(-1) (1/1) + 1/2 cot^(-1) (1/2) + 1/3 cot ^(-1) ( 1/3) " and " B = 1 cot^(-1) ( 1) + 2 cot^(-1) (2) + 3 cot^(-1) (3) " then " |B - A| " is equal to " (api)/b + c/d cot ^(-1) (3) where a,b,c,d in N are in their lowest form , find ( b -a - c - d)

Prove that : cot^(-1) 3 + cot^(-1).(3)/(4) = cot^(-1) .(1)/(3)

The sum of the infinite series cot^(-1)(7/4)+cot^(-1)((19)/4) +cot^(-1)((39)/4)....oo

Find tan^(-1)(3)+cot^(-1)(-1/3)+sec^(-1)2 .

A solution of the equation cot^(-1)2=cot^(-1)x+cot^(-1)(10-x)" where " 1 lt x lt 9 is : (a) 7 (b) 3 (c) 2 (d) 5

Prove: cot^(-1)(1/2)-1/2cot^(-1)(4/3)=pi/4

Prove that : cot^(-1)7+cot^(-1)8+cot^(-1)18=cot^(-1)3

Prove that : cot^(-1)7+cot^(-1)8+cot^(-1)18=cot^(-1)3