# Homework Help: Ellipse help

1. Dec 6, 2008

### chemic_23

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Dec 6, 2008

### mutton

Re: E-l-l-i-p-s-e h-e-l-p!

Remember the response I posted earlier:

1. Plug the points (x, y) into each equation properly.
2. You got rid of the 1 and didn't use it.
3. You'll need to solve a system of 2 equations to find a, b.

3. Dec 7, 2008

### chemic_23

Re: E-l-l-i-p-s-e h-e-l-p!

Thank you

Is this correct?

4. Dec 7, 2008

### HallsofIvy

Re: E-l-l-i-p-s-e h-e-l-p!

Check it yourself! It clearly has center (0,0). Do $(3, \sqrt{7})$ and $-\sqrt{3},3)$ satisfy that equation? That is, are
$$\frac{3^2}{30}+ \frac{(\sqrt{7})^2}{10}= 1$$
and
$$\frac{(\sqrt{3})^2}{30}+ \frac{3^2}{10}= 1$$ ?

And don't forget that you were told there were two possible answers. What is the other answer?

5. Dec 7, 2008

### chemic_23

I really don't have an idea... can you give me a hint please? I tried to equate both equation but still I got the same answer...