Practice Ellipse in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

The set of all points in a plane where the sum of the distances to two fixed points (foci) is constant. Standard form: (x−h)2a2+(y−k)2b2=1.

Imagine pinning two ends of a loose string to a board (these are the foci), then tracing a curve with a pencil keeping the string taut. The resulting oval shape is an ellipse. A circle is just a special ellipse where both foci coincide.

Showing a random 20 of 50 problems.

Example 1

medium
Find the foci of x2169+y2144=1.

Example 2

easy
Length of major axis of x264+y236=1?

Example 3

challenge
Find the equation of an ellipse with foci (0,±4) passing through (3,0).

Example 4

medium
Find the foci of x225+y216=1.

Example 5

medium
An ellipse has vertices (0,±6) and foci (0,±4). Find its equation.

Example 6

medium
Convert 16x2+25y2=400 to standard form.

Example 7

medium
Write the equation of an ellipse centered at the origin with foci at (±4,0) and a major axis of length 10.

Example 8

challenge
An ellipse has foci (±3,0) and passes through (0,4). Find its equation.

Example 9

medium
Find the center of (x−1)216+(y−3)225=1 and its foci.

Example 10

hard
Convert 4x2+9y2−16x+18y−11=0 to standard form.

Example 11

medium
Find the eccentricity of x2100+y264=1.

Example 12

easy
Find the lengths of the semi-major and semi-minor axes of the ellipse x225+y29=1.

Example 13

medium
Find the foci of the ellipse x216+y225=1.

Example 14

medium
Why is c2=a2−b2 (not a2+b2) for an ellipse?

Example 15

hard
Does the point (2,1) lie inside, on, or outside the ellipse x29+y24=1?

Example 16

easy
Find the vertices of x216+y24=1.

Example 17

easy
In x225+y29=1, what are a and b?

Example 18

medium
An ellipse has a=10 and e=25. Find c and b.

Example 19

hard
Find b for an ellipse with a=13 and a focus at (5,0) (center at origin).

Example 20

medium
Find the foci of (x−2)2169+(y+1)2144=1.