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:
[tex]y = mx + b[/tex]
We observe that the function is non-linear from [tex]x = 0[/tex] to [tex]x = 2.5[/tex].
Therefore, the interval for which the function is non-linear is given by:
[tex][0, 2.5][/tex]
Answer:
[tex][0, 2.5][/tex]
