Question

If `a_1, a_2,a_3, ,a_n` is an A.P. with common difference `d ,` then prove that `"tan"[tan^(-1)(d/(1+a_1a_2))+tan^(-1)(d/(1+a_2a_3))+tan^(-1)(d/(11+a_(n-1)a_n))]=((n-1)d)/(1+a_1a_n)`
A. `((n-1)d)/(1+ a_(1)a_(n))`
B. `(nd)/(1+ a_(1)a_(2))`
C. `((n+1)d)/(1+ a_(1)a_(n))`
D. None of these

Answer 1

Correct Answer - A