Thursday, May 26, 2011

Hyperbolas on a Coordinate Plane

Hello everyone! I'm posting again, this time on hyperbolas.



The hyperbola is the set of all points in a plane such that the difference of the distances from two fixed points (the foci) is constant.


There are two different types.




Horizontal Hyperbola

Vertical Hyperbola



Transverse Axis Length= 2a

Conjugate Axis Length=2b


Note: The a2 value is always the first denominator (not necessarily the larger) and the variable above the a2 indicates if the transverse axis is horizontal or vertical.


Here is the standard form for both a Horizontal Hyperbola and Vertical Hyperbola. For the horizontal hyperbola, the horizontal tranverse axis opens sideways. The vertical hyperbola, the vertical tranverse axis opens up and down.

The General Form of a Hyperbola: Ax2-By2+Cx+Dy+E=0

You could tell that this is a hyperbola because of the negative sign between the A and B unlike the parabola where the sign instead is positive.


The equation for the asymptotes is:




Let's look at an example now.

1) Let's graph 9x2 - 16y2 = 144.

First, multiply each side of the equation by 1/144 to put it in standard form.

x2 y2
-- - -- = 1
16 9

The direction of the hyperbola is horizontal. We now know that a = 4 and b = 3. The vertices are at (±4, 0). (Since we know the center is at the origin, we know the vertices are on the x axis.)

The easiest way to graph a hyperbola is to draw a box using the vertices and b, which is on the y-axis.

Draw the asymptotes through opposite corners of the box. Then draw the hyperbola.
The figure below is the graph of 9x2 - 16y2 = 144.



It's a lot more simple than it actually looks. Okay that's it! I didn't really do anything too fancy for this post so I hope that it's easy to understand. See you all tomorrow. :)























































No comments:

Post a Comment