I don't know how to identify the function in the graph.

Explanation
We are given the following graph:
We are required to identify the function in the graph.
This is achieved by graphing each function in the options using a graphing calculator as follows:
[tex]First\text{ }Option:y=-4x^4[/tex][tex]Second\text{ }Option:y=4x^4[/tex][tex]Third\text{ }Option:y=-5x^5[/tex][tex]Last\text{ }Option:y=5x^5[/tex]Hence, the answer is the last option.