A function is given by a table of values, a graph, a formula, or a verbal description. Determine whether it is one-to-one.
$ f(t) $ is your height at age $ t $.
It is not a $1-$ to- $-1$ function.
okay to figure out if this is a 1 to 1 function. Let's make a rough sketch of your height at various ages in your life. So let's assume that you grew for a certain amount of time and then perhaps your height stayed the same. And maybe at the end of your life, it went down well. If this is 1 to 1, then for every X value there's only one y value. And for every y value, there's only one X value, so it must pass the vertical line test and the horizontal line test. Since it's a function, it passes the vertical line test for every X value. There's only one y value, but it fails the horizontal line test because there are plenty of years in your life when you were the exact same height. So that's a fail. So no, this is not a 1 to 1 function