Answer: 
The function is odd. 
Explanation: 
A function is classified as odd if 

Graphically, this means if a function has a positive value at x = a (to the right of the y-axis), then it must have a negative value at x = -a (to the left of the y-axis).
To prove that our function is odd, we take a few examples from the graph

and so on.
Hence, our function is odd!