Answer:
0< x < 2.5
Explanation:
For this case we must find the interval for which the function is non-linear.
For this, we must define a linear function.
A linear function is a straight line that is generically:
y=mx+b
We observe that the function is non-linear from x = 0 to x = 2.5
Therefore, the interval for which the function is non-linear is given by:
[0,2.5]