Topic 9: Graphing Polynomial Functions Provide the missing information. A function $f$ is a function if for $a$ and $b$ in the domain of $f$, if $a \neq b$, then $f(a) \neq f(b)$. Answer: I PREVIOUS PAGE NEXT PAGE Quiz navigation

Step 1 ：The question is asking for the term that describes a function where no two different inputs ($a$ and $b$) produce the same output ($f(a)$ and $f(b)$). This is the definition of an injective function, also known as a one-to-one function.

Step 2 ：The missing information is 'injective' or 'one-to-one'. So, a function $f$ is an 'injective' or 'one-to-one' function if for $a$ and $b$ in the domain of $f$, if $a \neq b$, then $f(a) \neq f(b)$.

Step 3 ：\(\boxed{\text{The missing information is 'injective' or 'one-to-one'}}\)