The sentence in the image says:
"A function whose rate of change is not constant is a Select Choice function."

Based on this description, the correct vocabulary term you need is likely "nonlinear" because a nonlinear function has a rate of change that is not constant. In contrast, linear functions have a constant rate of change.

Would you like further details or have any additional questions?

Related Questions:

1. What are the key characteristics of a nonlinear function?
2. How does the rate of change differ between linear and nonlinear functions?
3. Can you provide examples of real-life nonlinear functions?
4. How do you calculate the rate of change for nonlinear functions?
5. What are the differences between exponential and polynomial nonlinear functions?

Tip: To identify a nonlinear function from a graph, check if the curve is not a straight line. A curved graph often indicates a nonlinear function.