To solve this problem you must apply the proccedure shown below:
1. You have to find the distance from the center to the focus, as below:
c=√(a^2-b^2)
Where a is the major radius and b is the minor radius.
2. Therefore, by the graph, you have:
a=6
a^2=36
b=3
b^2=9
3. When you substitute the values, you obtain:
c=5.2
4. As you can see in the graph, the coordinates of the center is (3,4), then, the locations of the foci:
3+c=8.2
3-c=-2.2
The answer is: (-2.2,4) and (8.2,4)