so my equation is x^{2}+y^{2}-4x+2y-4=0

i know the formula is (x-h)^{2}+(y-k)^{2}=r^{2}

x^{2}-4x+y^{2}+2y-4=0

the Y is (y-2)^{2}which makes my k equal to positive 2 just having trouble with the h and radius

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- October 20th 2012, 09:38 AMM670Need help finding (h,K,) and the radius of a circle
so my equation is x

^{2}+y^{2}-4x+2y-4=0

i know the formula is (x-h)^{2}+(y-k)^{2}=r^{2}

x^{2}-4x+y^{2}+2y-4=0

the Y is (y-2)^{2}which makes my k equal to positive 2 just having trouble with the h and radius - October 20th 2012, 09:50 AMskeeterRe: Need help finding (h,K,) and the radius of a circle

complete the square for x and y ...

finish it ... - October 20th 2012, 10:03 AMSorobanRe: Need help finding (h,K,) and the radius of a circle
Hello, M670!

Sorry, your algebra is off . . .

Quote:

We must "complete the square".

The circle has center and radius

- October 20th 2012, 10:33 AMM670Re: Need help finding (h,K,) and the radius of a circle
ok I understand that question but given this example here 5 x^2 - 10 x +5 y^2 - 8 y - 6 = 0 .

I worked it down to (x-1)^2 and (y-0.8)^2 =

I divided out 5 and was left with x^2-2x+y^2-1.6y-1.2=0

then its x^2-2x+1 + y^2-1.6y ?= 1.2-1 (?) - October 20th 2012, 11:01 AMPlatoRe: Need help finding (h,K,) and the radius of a circle
- October 20th 2012, 11:13 AMM670Re: Need help finding (h,K,) and the radius of a circle
- October 20th 2012, 11:15 AMM670Re: Need help finding (h,K,) and the radius of a circle
How do you figure it out when you have a fraction or decimal to complete the squares?

- October 20th 2012, 11:23 AMPlatoRe: Need help finding (h,K,) and the radius of a circle