# Foci of a hyperbola

2 videos
2 skills
Learn about the foci of the hyperbola: How to find them from the hyperbola's equation and how to find the equation when given the foci.

### Finding the foci of a hyperbola from its equation

VIDEO 15:24 minutes
Sal discusses the foci of hyperbolas and shows how they relate to hyperbola equations.

### Find the foci of a hyperbola from its equation

PRACTICE PROBLEMS
Given the equation of a hyperbola, find its foci.

### Write the equation of a hyperbola from its features

PRACTICE PROBLEMS
Given some features of a hyperbola, find its equation.

### Proof of the hyperbola foci formula

VIDEO 14:50 minutes
Sal proves why, for the general hyperbola equation x^2/a^2-y^2/b^2=1, the focal length f forms the equation f^2=a^2+b^2 with the parameters a and b.