# E(m)=(pi/2)2F1(-1/2,1/2;1;m)

The following formula holds: $$E(m) = \dfrac{\pi}{2} {}_2F_1 \left( - \dfrac{1}{2}, \dfrac{1}{2};1;m \right),$$ where $E$ denotes Elliptic E, $\pi$ denotes pi, and ${}_2F_1$ denotes hypergeometric2F1.