Answer:
is a function with a slope that is not constant.
Explanation:
A linear function has a positive relationship and as such an increase in one variable (input variable) causes an increase in the other variable (output variable) i.e the variables are directly proportional. Thus, the graph of a linear function is a straight-line and its slope is always constant.
On the other hand, nonlinear function has a negative relationship and as such an increase in one variable (input variable) causes a decrease in the other variable (output variable) i.e the variables are inversely proportional.
This ultimately implies that, the graph of a nonlinear is a curved line and whose direction is constantly changing.
Hence, a nonlinear function is a function with a slope that is not constant. An example of a nonlinear function is a quadratic function or equation.