# Math Help - How would I graph this?

1. ## How would I graph this?

How would I go about graphing the equation:

$5x^2+9y^2=45$

?

2. Originally Posted by deathtolife04
How would I go about graphing the equation:

$5x^2+9y^2=45$

?

If you are using a graphing calculator, solve for y:
$y = \pm \sqrt{5 - \frac{5}{9}x^2}$

So graph the two pieces:
$y_1 = \sqrt{5 - \frac{5}{9}x^2}$
and
$y_2 = - \sqrt{5 - \frac{5}{9}x^2}$

Otherwise
$5x^2+9y^2=45$

$\frac{x^2}{3^2} + \frac{y^2}{(\sqrt{5})^2} = 1$
is an ellipse with $a = 3 \text{ and }b = \sqrt{5}$ centered on (0, 0).

-Dan

3. ## Re:

Originally Posted by deathtolife04
How would I go about graphing the equation:

$5x^2+9y^2=45$

?
You can do 2 ways...

1. Solve for "Y"

or

2. Switch X & Y and then flip the graph 90˚ and over...

Re: