The value of Σ 1/√4n^2-r^2 ; r=0, n-1 as n → ∞ is

Question

The value of \(\sum\limits_{r = 0}^{n-1} \frac1{\sqrt{4n^2 - r^2}}\) as n → ∞ is

a. π/3

b. π/6

c. π/4

d. none of these

Answer 1

Correct option is b. π/6