Sketch the graphs of the following function:

9x^2-7x+y^2-4y+112=0

Any help/or complete working out would be appreciated!

I have tried to do this and failed.

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- Dec 15th 2010, 02:02 PMJoker37ellipses
Sketch the graphs of the following function:

9x^2-7x+y^2-4y+112=0

Any help/or complete working out would be appreciated!

I have tried to do this and failed. - Dec 15th 2010, 04:49 PMsnowtea
Use completing the square to change the function into something like:

9(x - a)^2 + (y - b)^2 = c

Can you first figure out where the center of the ellipse is? - Dec 15th 2010, 07:02 PMSoroban
Hello, Joker37!

I bet that the "112" should be negative . . . even then, the answer is ugly!

You were assigned this problem with absolutely**no**instructions?

*How cruel!*

Quote:

We have: .

Complete the square: .

. .

. . . . . .

. . . . . .

Divide by

. .

. .

. .

. .

. .

- Dec 16th 2010, 03:36 AMHallsofIvy
Actually, as it is written, it is

**very**easy- the graph is the empty set! - Dec 16th 2010, 06:19 PMJoker37
- Dec 17th 2010, 02:12 PMJoker37
Hi everybody!

I'm still stuck with this problem and unfortunately I have no-body to help me. I feel so alone.

Anyway, if it's because the question doesn't make sense or something like that please tell me and I will skip this question but I just don't like knowing that I don't know how to do something. - Dec 17th 2010, 06:08 PMEducated

If you look carefully at the equations used, you will notice that and are different equations.

If you expand and simplify the simplified one, you will get: which I'm guessing is the equation you are trying to graph and that the one in the first post has a typing error?

Now that Soroban has supplied you with a method, why don't you give it a try yourself? - Dec 17th 2010, 06:39 PMSoroban
Hello, Joker37!

Quote:

. .

Well, that certainly explains a lot!

First of all, the original equation had a typo

. . It was not*7x*, but.*72x*

Second, their answer is quite.*stupid*

. . That is definitely**not**the simplfied answer.