29 Numerics library [numerics]

29.9 Mathematical functions for floating-point types [c.math]

29.9.5 Mathematical special functions [sf.cmath]

29.9.5.5 Complete elliptic integral of the second kind [sf.cmath.comp_ellint_2]

double comp_ellint_2(double k); float comp_ellint_2f(float k); long double comp_ellint_2l(long double k);

Effects: These functions compute the complete elliptic integral of the second kind of their respective arguments k.

Returns:

E(k)=E(k,π/2),for |k|1

where k is k.