Given the graph of a function, you need to remember that, by definition, the zeros of a function are the x-intercepts (where the function intersects the x-axis).
In this case, you can identify that the function intersects the x-axis at these points (approximately):
[tex]\begin{gathered} (1,0) \\ (4,0) \end{gathered}[/tex]
Therefore, the roots are, approximately:
[tex]\begin{gathered} x_1\approx1 \\ x_2\approx4 \end{gathered}[/tex]
Hence, the answer is:
[tex]\begin{gathered} x_1\approx1 \\ x_2\approx4 \end{gathered}[/tex]
