# Exponential Functions

## Vocabulary

### asymptote

line that a graph approaches as one of the variables approaches infinity or negative infinity

### base of an exponential function

value of $b$ in a function of the form $f(x)=ab^x$, where $a$ and $b$ are real numbers, $a\neq 0$, $b>0$, and $b\ne1$

### compound interest

interest calculated on both the principal (the initial amount of money invested or lent) and any previously earned interest

### decreasing function

function in which the $y$-values decrease as the $x$-values increase

### exponential decay

decrease in a quantity by a constant percent rate per unit of time

### exponential function

function, where $a$ and $b$ are real numbers, $a\neq 0$, $b>0$, and $b\ne1$, written in the form:
$f(x)=ab^x$

### exponential growth

increase in a quantity by a constant percent rate per unit of time

### exponential regression

mathematical process for finding the equation of an exponential function that best models a data set

### exponential relationship

nonlinear relationship for which an exponential function is an appropriate model

### increasing function

function in which the $y$-values increase as the $x$-values increase

### parent function

function of a certain type that has the simplest algebraic rule

### transformation

change of the graph of a function