Question

NO LINKS!! Please help me with this one​

Answer 1

The letter a in an ellipse equation is:

• Half of the major axis if a > b and the ellipse is horizontal, or
• Half of the minor axis if b > a and the ellipse is vertical.

Explanation:

General equation of an ellipse

`((x-h)^2)/(a^2)+((y-k)^2)/(b^2)=1`

where:

• center = (h, k)

• Vertices = (h±a, k) and (h, k±b)

• Foci = (h±c, k) or (h, k±c) where c²=a²−b²

If a > b the ellipse is horizontal, a is the major radius, and b is the minor radius.

If b > a the ellipse is vertical, b is the major radius, and a is the minor radius.

The major axis is the longest diameter of an ellipse, so the major radius is one half of the major axis.

The minor axis is the shortest diameter of an ellipse, so the minor radius is one half of the minor axis.

Therefore the letter a in an ellipse equation is:

• The major radius (half of the major axis) if a > b and the ellipse is horizontal, or
• The minor radius (half of the minor axis) if b > a and the ellipse is vertical.