Substituting formula_20 and formula_21 into the equation above and integrating with respect to formula_22 from 0 to 1 gives::formula_23The value K(k) is the complete elliptic integral of the first kind.
Вводим formula_20 и formula_21 и интегрируем по formula_22 от 0 до 1:: formula_23Величина K(k) есть полный эллиптический интеграл первого рода.