15.4 Hyperbola
Hyperbola
Basic concepts:
 Pythagorean identities
 Ellipse
 Circle
Lessons
Notes:
hyperbola: the difference of the distances from any point on a hyperbola to each focus is constant and equal to the transverse axis $2a$.
ellipse: the sum of the distances from any point on an ellipse to each focus is constant and equal to the major axis $2a$.
$c= \sqrt{a^2  b^2}$ $c$: distance from the center to a focus
$e= \frac{c}{a}$ $e$: eccentricity; the larger the value of $e$, the straighter the hyperbola

2.
properties of a hyperbola
$(\frac{x6}{4})^2 + (\frac{y+5}{3})^2=1$