ANSWER
The function is non linear.
EXPLANATION
A linear function is of the form
[tex]y = mx + c[/tex]
or
[tex]ax + by + c = 0[/tex]
The highest degree of the variables in each term in the simplest form is 1.
Any degree higher or less than 1 will make the function nonlinear.
The function given to us is,
[tex]y = 2{x}^{2} - 4[/tex]
The highest degree is 2. This is a quadratic curve.
The graph of all linear functions are straight lines.
