" Prove that,"cot^(-1)7+cot^(-1)8+cot^(-1)18=cot^(-1)3@

Prove that: cot^(-1)7+cot^(-1)18=cot^(-1)5 .

Prove that cot^-1 7 + cot^-18 + cot^-118 = cot^-1 3 .

Find- cot^(-1)1+cot^(-1)2+cot^(-1)3

The sum of the series cot^(-1)2+cot^(-1)8+cot^(-1)18+cot^(-1)32.........

Prove that 2cot^(-1)5+ cot^(-1)7 + 2cot^(-1)8 =pi/4

Prove that cot^(-1)(3)-cot^(-1)(4)=cot^(-1)(13)

Let S_(n)=cot^(-1)2 +cot^(-1)8 +cot^(-1)18 +cot^(-1)32+…. to n^(th) term. Then lim_(n to oo)S_(n) is

If cot^(-1) ( alpha) = cot^(-1)(2) + cot^(-1)(8) + cot^(-1)(18) + cot ^(-1)(32) + "…………" upto 100 terms , then alpha is :