`l isum_(n-gtoo)sum_(r=1)^n1/(sqrt(4n^2-r^2))`
`l isum_(n-gtoo)sum_(r=1)^n1/(sqrt(4n^2-r^2))`
A. `(pi)/(6)`
B. `(pi)/(4)`
C. `(pi)/(3)`
D. `(pi)/(2)`
4 views
1 Answers
Correct Answer - A
`S=underset(nrarroo)(lim)sum_(r=0)^(n-1)(1)/(sqrt(4n^(2)-r^(2)))`
`rArr" "S=(1)/(n)underset(nrarroo)(lim)sum_(r=0)^(n-1)(1)/(sqrt(2^(2)-((r)/(n))^(2)))`
`rArr" "S=int_(0)^(1)(dx)/(sqrt(2^(2)-x^(2)))`
`rArr" "S=[sin^(-1).(x)/(2)]_(0)^(1)=sin^(-1).(1)/(2)-sin^(-1)`
`rArr" "S=(pi)/(6)`
4 views
Answered