C++ How to Program, 10/e

... Performing the Interest Calculations with Standard Library Function pow

The for statement (lines 22–28) executes its body 10 times, varying the unsigned int control variable year from 1 to 10 in increments of 1. This loop terminates when year becomes 11. Variable year represents n in the problem statement.

C++ does not include an exponentiation operator, so we use the standard library function pow (line 24) from the header <cmath>. The call pow(x, y) calculates the value of x raised to the yth power. The function receives two double arguments and returns a double value. Line 24 performs the calculation $\mathit{a}=\mathit{p}{(1+\mathit{r})}^{\mathit{n}}$, where a is amount, p is principal, r is rate and n is year.

The body of the for statement contains the calculation 1.0 + rate as pow’s first ...