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

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

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

Prove that cot(pi/4-2cot^(- 1)3)=7

Prove that cot(pi/4-2cot^(- 1)3)=7

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

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

Prove that sin cot^(-1) tan cos^(-1) x = sin cosec^(-1) cot tan^(-1) x = x, " where " x in [0,1]

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

Find the sum cot^(-1) 2 + cot^(-1) 8 + cot^(-1) 18 + ...oo

Prove that : cot^(-1)((1+ab)/(a-b))+cot^(-1)((1+bc)/(b-c))+cot^(-1)((1+ca)/(c-a))=pi,(a>b>c>0)