Answer:
d. 16x² + y² = 16
Step-by-step explanation:
Standard form of an ellipse is:
x² / a² + y² / b² = 1
If b > a, the ellipse has a vertical orientation.
We can ignore options b and c, since they have minus signs in them.
Convert the other options to standard form:
a. x² / (1/16) + y² / (1/25) = 1
x² / (1/4)² + y² / (1/5)² = 1
1/4 > 1/5
d. x² + y² / 16 = 1
x² / 1² + y² / 4² = 1
1 < 4
e. x² / 16 + y² = 1
x² / 4² + y² / 1² = 1
4 > 1
Of these three options, only d is a vertical ellipse.
