Answer:
[tex]f(x) = x^{2} - 1[/tex]
Step-by-step explanation:
The definition of even function is: [tex]f(x) = f(-x)[/tex]
I am going to assume the second option is [tex]f(x) = x^{2} - 1[/tex] and the answer.
[tex]f(x) = x^{2} - 1\\f(-x) = (-x)^{2} - 1 = x^{2}-1[/tex]