This is the most basic form of an absolute value function. If you see that the only expression inside the absolute value symbol is just "x", assume that the vertex of the graph will occur when x = 0.
Or, if you want to use the formula above to find the vertex, rewrite the given function in the standard form so that you can identify the values of m, b and c.
The vertex is calculated as
Since x = 0, this becomes the center values of all x's. Now we can pick some numbers to the left and to the right of zero. I would suggest to use equal amounts of numbers that are of the same increment.
Pick -3, -2, -1 to the left of zero, and +1, +2, +3 to its right. Evaluate all values of x into the function to get the corresponding y-values.
Notice that the graph has a low point determined by the middle x-value which is the x-coordinate of the vertex itself, i.e. (0,0).