\[begin{array}{l} Cost{\text{ }}of{\text{ }}trade{\text{ }}credit = \ \left( {\left\[ {\frac{{1 + {\text{ }}\left( {% discount} \right)}}{{\left( {1 - % discount} \right)}}} \right\] \times \frac{{365}}{{days{\text{ }}past{\text{ }}discount{\text{ }}}} - 1} \right) end{array}\]