# 3.5.1.3.27 Elliptic_integral_rf

## Definition:

$Rf=elliptic\_integral\_rf(x,y,z)$ calculates an approximation to the integral

$R_F(x,y,z)=\frac 12\int_0^\infty \frac{dt}{\sqrt{(t+x)(t+y)(t+z)}}$

where x, y, z ≥ 0 and at most one is zero.

$R_F(x,y,z)=\frac 12\int_0^\infty \frac{dt}{\sqrt{(t+x)(t+y)(t+z)}}$