[tex] \frac{x^{2} }{36} [/tex] + [tex] \frac{ y^{2}}{16} [/tex] = 1
This is because the standard form of an ellipse is
[tex] \frac{ x^{2} }{ a^{2} } [/tex] + [tex] \frac{ y^{2} }{ b^{2} } [/tex] = 1
where a is the vertex and b is the co-vertex. So when we stick their respective x and y values in and then square them, you're left with the answer above.