Answer:
A) x²/9 -y²/4 = 1
Step-by-step explanation:
The distance from center to one vertex is half the difference of the distances from a point to either focus. That is, the distance from center to the vertex is 3 on the x-axis, so the x-term is (x/3)² = x²/9.
In the picture, ...
... c² = a² + b²
The problem statement tells us c = √13, so we know c² = 13. Then ...
... b² = c² - a² = 13 -9 = 4
and the y-term is y²/4.
Thus, the equation is ...
... x²/9 - y²/4 = 1
_____
You knew that was the correct choice as soon as you knew the x-term.
