Answer
f is even.
Work Step by Step
We know that if a graph satisfies the condition, $ f\left( x \right)=f\left( -x \right)$, then the function is said to be an even function. And for an even function, the graph of the function is symmetric with respect to the y-axis.
Also, if a graph satisfies the condition, $ f\left( x \right)=-f\left( -x \right)$ then the function is said to be an odd function. For an odd function, the graph of the function is symmetric with respect to the origin.
The provided graph of the function is symmetric with respect to the y-axis.
Hence, it is concluded that the function $ f $ is an even function.