# Find help: Find the equation of the circle whose diameter endpoints are (-4,3) and (2,-5). - Help.com

## Find the equation of the circle whose diameter endpoints are (-4,3) and (2,-5).

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Shoot.. i used to be able to do stuff like this in the blink of an eye, but I guess being out of school for a while as led me to forget… Sorry. Do you have the standard equation for circles handy? All i’d need to help you is that.

find the distance between the two points, this will give you the diameter. Half to diameter is the radius (r).
Find the midpoint of the two points, this will give you the centre point of the circle (h,k).
The substitute these values into the equation : (x-h)^2 + (y-k)^2 = r^2

Help me with: Let down, again.

Ginseng is right, and in case you don’t have all those equations:

Distance between two points is d = sqrt( (y1 - y2)^2 + (x1 - x2)^2 ) , where sqrt means square root.

Midpoint is ( ( x1 + x2 ) / 2 , ( y1 + y2 ) / 2 ).

Good luck!

(-2,-2)

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x coordinate of C = (-1 + 3) /2 = 1

y coordinate of C = (2 + 2) / 2 = 2

The radius is half the distance between A and B.

r = (1/2) ([3 - (-1)]2 + [2 - 2]2 )1/2

= (1/2)(42 + 02)1/2

= 2

help please: how do find the distance between A and B?

dood, this post was written over 8 months ago. I think he’s got it covered.

You have probably Got the question done by now but none the less I will post this comment for others out there!

Firstly You must find the centre of the Circle which is the midpoint of A and B:

(X1+X2/2,Y1+Y2/2) This Gives you the Centre.

Secondly find the distance from the centre of the Circle to either point A or B. This gives you the Radius of the circle.

IACI = SQUAREROOT of (X2-X1)squared + (Y2-Y1)squared

Now we have the centre and the radius of the circle we can now find the equation.

equation of circle whose centre is NOT (0,0) :

(X-H)sqrd + (Y-K) sqrd = Rsqrd

In this question the actual answer is:

Centre: (1,-1)
Equation: (x-1)2+(y+1)2=41

First you should describe your question then I will give you answer.
_______________________________
Matt
a href=”http://www.smartloc.net”rel=”dofollow”> Wide Circles /a>

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its simple
let first point be(x1,y1),and second be(x2,y2).
then equation of circle = [(x-x1)*(x-x2)]+[(y-y1)*(y-y2)]
see its so simple !!!!

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papoekjl;as;gjasdlhg

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ginseng wrote:
find the distance between the two points, this will give you the diameter. Half to diameter is the radius (r).
Find the midpoint of the two points, this will give you the centre point of the circle (h,k).
The substitute these values into the equation : (x-h)^2 + (y-k)^2 = r^2

hi i know this was a long time ago, but i’m not sure about the last bit : x-h and y-k what are the x and y?

:)

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thank you!!!

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**** titties!

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this is hard yo

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I have these endpoints (-2,-4), (4,6) and I need to find the equation of the circle can anyone help me?

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