Exponential Function
A function that changes by multiplying by the same factor over equal input intervals.
Initial Value
The starting output, often the value when x=0. In y=ab^x, it is a.
Growth Factor
The number multiplied each step when an exponential function increases. In y=ab^x, it is b when b>1.
Growth Rate
The percent increase compared with the previous amount. A 20% growth rate uses a factor of 1.20.
Decay Factor
The number multiplied each step when an exponential function decreases. In y=ab^x, it is b when 0<b<1.
Decay Rate
The percent decrease from the previous amount. A 30% decay rate means the factor kept is 0.70.
Constant Ratio
The repeated factor between consecutive output values in an exponential table.
Rate of Change
How much the output changes per 1-unit input change. Exponential functions do not have a constant rate of change.
Linear Pattern
A pattern with equal differences between output values over equal input intervals.
Geometric Sequence
A sequence where each term is found by multiplying the previous term by the same factor.
Recursive Rule
A rule that gives the first term and explains how to use one term to find the next term.
Explicit Rule
A rule that lets you find any term or output directly from the input.