Standard Form of Equation of the Circle

mathxyz · 2024-03-01 10:59:06

Find the standard form of the equation of the circle centered at the origin and containing the point (-2, 3).

Let's do this one.

The standard form is x^2 + y^2 = r^2.

I need to find r.

r = sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}

r = sqrt{(-2 - 0)^2 + (3 - 0)^2}

r = sqrt{(-2)^2 + (3)^2}

r = sqrt{4 + 9}

r = sqrt{13}

Plug sqrt{13} into x^2 + y^2 = r^2 for r.

x^2 + y^2 = (sqrt{13})^2

x^2 + y^2 = 13

Yes?

Bob · 2024-03-01 20:30:07

You keep doing the hard bit ok then going back to the wrong circle equation.

You need (x-g)^2 + (y-h)^2 = r^2 for all the questions.

Bob

mathxyz · 2024-03-02 18:13:06

Bob wrote:

You keep doing the hard bit ok then going back to the wrong circle equation.
You need (x-g)^2 + (y-h)^2 = r^2 for all the questions.
Bob

Ok.

I will use (x - h)^2 + (y - k)^2 = r^2.

(x - (-2))^2 + (y - 3)^2 = 13

(x + 2)^2 + (y -3)^2 = 13

Yes?

Bob · 2024-03-03 04:38:41

Sorry, my mistake ... didn't read the question properly. This one was correct to start with. It's the others that needed that change.

Bob

mathxyz · 2024-03-03 18:22:19

Bob wrote:

Sorry, my mistake ... didn't read the question properly. This one was correct to start with. It's the others that needed that change.
Bob

Can you please show the correct equation?

Bob · 2024-03-03 21:15:09

x^2 + y^2 = 13

In other words you answered correctly.

I was working from a phone rather than a laptop which makes it harder to have many windows open and the text size is small.

I'd noticed you had worked out all you needed in several questions but given an answer centred on the origin rather than another point. To save myself a lot of effort I thought I'd just pick one question to explain the problem. Unfortunately the one I picked was centred on the origin. Whoops my error. Soon I'll be back on a laptop which'll makes it easier.

Bob

mathxyz · 2024-03-04 01:43:47

Bob wrote:

x^2 + y^2 = 13
In other words you answered correctly.
I was working from a phone rather than a laptop which makes it harder to have many windows open and the text size is small.
I'd noticed you had worked out all you needed in several questions but given an answer centred on the origin rather than another point. To save myself a lot of effort I thought I'd just pick one question to explain the problem. Unfortunately the one I picked was centred on the origin. Whoops my error. Soon I'll be back on a laptop which'll makes it easier.
Bob

What happened to your laptop?
I don't have a laptop or a computer. Every question
you see here is typed using my cell phone.
I still have no idea how to upload photos here.
When are you going to upgrade the website to make uploading of photos easier for members.

amnkb · 2024-03-05 12:54:51

FelizNYC wrote:

I still have no idea how to upload photos here.

Follow the steps here

FelizNYC wrote:

When are you going to upgrade the website to make uploading of photos easier for members.

fluxbb isnt being developed any more [link]
So maybe it cant be upgraded

mathxyz · 2024-03-05 18:16:52

amnkb wrote:

FelizNYC wrote:
I still have no idea how to upload photos here.
Follow the steps here
FelizNYC wrote:
When are you going to upgrade the website to make uploading of photos easier for members.
fluxbb isnt being developed any more [link]
So maybe it cant be upgraded

Thanks but I am not going through all those steps.

Math Is Fun Forum

#1 2024-03-01 10:59:06

Standard Form of Equation of the Circle

#2 2024-03-01 20:30:07

Re: Standard Form of Equation of the Circle

#3 2024-03-02 18:13:06

Re: Standard Form of Equation of the Circle

#4 2024-03-03 04:38:41

Re: Standard Form of Equation of the Circle

#5 2024-03-03 18:22:19

Re: Standard Form of Equation of the Circle

#6 2024-03-03 21:15:09

Re: Standard Form of Equation of the Circle

#7 2024-03-04 01:43:47

Re: Standard Form of Equation of the Circle

#8 2024-03-05 12:54:51

Re: Standard Form of Equation of the Circle

#9 2024-03-05 18:16:52

Re: Standard Form of Equation of the Circle

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