26 Numerics library [numerics]

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

26.8.6 Mathematical special functions [sf.cmath]

26.8.6.5 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:
where k is k.