Identify the equation, foci, vertices, and asymptotes of a hyperbola.
A hyperbola is the set of all points where the absolute difference of distances from two fixed foci is constant. Unlike an ellipse, a hyperbola has two separate branches and two asymptotes.
Horizontal Hyperbola
Vertical Hyperbola
Horizontal hyperbola (x² positive). a² = 9, b² = 16, so a = 3, b = 4. Vertices: (±3, 0). c = √(9+16) = 5. Foci: (±5, 0). Asymptotes: y = ±(4/3)x.
Key difference from ellipses: for hyperbolas, c² = a² + b² (c is largest). For ellipses, c² = a² − b² (c is smallest). Watch the sign in the equation.
For the hyperbola y²/4 − x²/9 = 1, which direction do the branches open?