A review of the time series of the Peruvian economic process shows that private investment has an inverse behavior to that of total external debt. Resident economic actors and potential foreign investors, upon observing levels of indebtedness that exceed the ability to pay, reduce investment, which has consequences on the economic growth rate. In the growth equation, introducing the indicator of external debt over GDP squared in order to simulate the Laffer curve, it was found that from 44% of debt over GDP, the indicator is associated with negative growth rates.

Financial Mathematics has a wide field of application in all disciplines and especially in the economic and financial sector that involves the central variable of capital, expressed in money, which assumes different values over time according to an interest rate agreed by the parties, debtor and creditor. Financial Mathematics is a science of daily application in the life of individuals and companies, so it is essential to understand it thoroughly, because the mistakes made with them have a direct impact on the expected results. The study of financial mathematics will allow the user, professional or student, to acquire the necessary knowledge to understand the implications of the variations in the value of money over time.