### argument of a logarithm

expression a logarithm applies to. For example, the argument of $\log_4(x-3)$ is $x-3$.

### exponential equation

equation with an exponential expression that has a variable in the exponent

### logarithmic equation

equation with a logarithmic expression that contains a variable

### zero of a function

any input value of a function that makes the output of the function equal zero