Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
A hyperbola is the set of all points in a plane, the difference of whose distances from two fixed points (foci) in the plane is a constant. This constant is denoted by .
The line through the foci is called the transverse axis, and the line through the center and perpendicular to the transverse axis is called the conjugate axis.
The distance between the two foci is , the distance between the two vertices is , and the length of the conjugate axis is . These are related by the equation .
The eccentricity of a hyperbola is the ratio of the distance from the center to a focus to the distance from the center to a vertex, given by . For every hyperbola, .
The latus rectum of a hyperbola is a line segment perpendicular to the transverse axis through any of the foci, with its endpoints lying on the hyperbola.
📐Formulae
💡Examples
Problem 1:
Find the coordinates of the foci and the vertices, the eccentricity, and the length of the latus rectum for the hyperbola .
Solution:
Comparing with , we get and . Therefore, and . We find .
- Vertices:
- Foci:
- Eccentricity:
- Length of Latus Rectum:
Explanation:
Identify the orientation (horizontal since is positive), extract and , calculate using the hyperbola identity, and apply standard coordinate formulae.
Problem 2:
Find the equation of the hyperbola with foci and conjugate axis of length .
Solution:
Since the foci are on the -axis, the transverse axis is along the -axis. The general equation is . Given foci . Given length of conjugate axis . Using , we have: Therefore, the equation is:
Explanation:
Determine the orientation from the foci. Use the given conjugate axis length to find . Solve for using the relationship between , then substitute into the vertical hyperbola standard form.