Answer
$f(x)$ is even.
Work Step by Step
$ f(x)$ is odd if $f(-x)=-f(x)$
$ f(x)$ is even if $f(-x)=f(x)$
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$f(x)=x^{2}-3$
$f(-x)=(-x)^{2}-3=x^{2}-3=f(x)$
$f(x)$ is even.
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