Math Is Fun Forum

RandomPieKevin

Member

Registered: 2015-07-02

Posts: 29

Two circles' intersection

The circles

and

intersect in two points A and B. Find the slope of

.

I got

, but I don't know what do do next! (\pm is plus or minus, and it's from the quadratic equation). I got that answer by expanding the second equation and using the first equation to find what x^2 and x are in terms of y. Then, I substituted them in and solved. I don't know what to do next now.

Can someone help me solve this? Thanks.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Two circles' intersection

Hi;

Some hints:

1) Always draw a good diagram first. Download and learn to use Geogebra, it is the big boy on the block!

2) I posted to you already how to use latex, that will help.

3) In math neat work is a must, that is why latex helps.

4) I am getting a slope of - 2 / 3

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

RandomPieKevin

Member

Registered: 2015-07-02

Posts: 29

Re: Two circles' intersection

Wait, where did you post the LaTeX help? <-----
____________________________________________________________________________________________________________________________________________________________

I got the Geogebra thing. I've used Geogebra before, but not the spreadsheet. I've learned it now. Thanks.

Last edited by RandomPieKevin (2015-07-27 02:41:25)

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Two circles' intersection

http://www.mathisfunforum.com/viewtopic … 09#p364909

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Two circles' intersection

Thanks Bob!

RandomPieKevin

Did you find it?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

RandomPieKevin

Member

Registered: 2015-07-02

Posts: 29

Re: Two circles' intersection

Yup! Thanks! I will be using it from now on!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Two circles' intersection

Please show how you arrived at your answer for y in post #1.

I've used Geogebra before, but not the spreadsheet.

The spreadsheet is not required for this.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

RandomPieKevin

Member

Registered: 2015-07-02

Posts: 29

Re: Two circles' intersection

I have solved this. Thank you for the help.

***This topic is now resolved***