From the graph, we can see that those values of x for f(x) = 6, are, x = 0, and x = 2.
We can see that this is the representation of a quadratic function, and in such a function there will be two equal values for two different values of x.
Therefore, in this case, the values of x for f(x) = 6 are x = 0, and x = 2.
We can follow the next steps (to answer this question):
1. We need to find in the graph the value for f(x) = 6. We see that we have two values for which f(x) = 6.
2. From the graph, we know that at x = 0, the value of the function is 6, or f(0) = 6.
3. From the graph, we know that at x = 2, the value of the function is also 6, or f(2) = 6.
Then, the values of x for which f(x) = 6 are x = 0, and x = 2.