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Reference Tables for Pre-Calculus

Interest, Growth and Decay

Compound Interest

where
P = the initial amount of the investment or loan
r = the annual rate of interest (expressed as a decimal)
n = number of times per year that the interest is paid (compounded)
t = the number of years for which the money is invested or borrowed
A = the amount of money accumulated after t years, including interest

Continuous Interest, Growth and Decay

where
P = the initial amount of the investment or loan
e = the base of the natural logarithm
r = the annual interest rate or the rate of growth or decay
t = the time, in years
A = the amount accumulated after t years