Consider this formula for finding the total amount of money generated by an account receiving compound interest:

A = 200(1 + 0.08/1)^1*t. When comparing to y = a(1+r)^t, the general formula for exponential growth, which part of the compound interest formula compares best with the variable?

1 answer

In the formula you provided for compound interest:

\[ A = 200\left(1 + \frac{0.08}{1}\right)^{1 \cdot t} \]

we can simplify this to:

\[ A = 200(1.08)^t \]

This resembles the general formula for exponential growth:

\[ y = a(1 + r)^t \]

where:

  • \( a \) is the initial amount (the principal),
  • \( r \) is the rate of growth,
  • \( t \) is time.

In your compound interest formula, the components compare as follows:

  • The initial amount \( a \) corresponds to 200.
  • The growth factor \( r \) corresponds to 0.08 (which represents an 8% interest rate).
  • The variable \( t \) is time, which remains the same in both formulas.

Thus, in this context, the part of the compound interest formula that compares best with the variable \( t \) is \( t \) itself, as both expressions indicate the same concept of time passing for the growth of the investment or account.