Observe the table :
\Formula for rate of change : .
Substitute and
in rate of change formula.
The rate of change is .
Substitute and
in rate of change formula.
The rate of change is .
Substitute and
in rate of change formula.
The rate of change is .
Substitute and
in rate of change formula.
The rate of change is .
The rate of change is not constant.
\Thus, the function is Non-linear.
\No; the -values do not increase at a constant rate.