Answer
See graph and explanations.
Work Step by Step
Step 1. Given $\frac{x^2}{49}+\frac{y^2}{81}=1$, we can identify $a^2=81, b^2=49$; thus $c=\sqrt {a^2-b^2}=4\sqrt 2$. The ellipse is centered at $(0,0)$ with a vertical major axis.
Step 2. We can graph the equation as shown in the figure, and the foci can be located at $(0, \pm4\sqrt 2)$
