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#1 2006-10-30 02:51:18

unique
Member
Registered: 2006-10-04
Posts: 419

circle

Find the equation of teh circle whose center is at (3,2)
and whose radius is 5.
the answer has ot be in standard form.
can anyone tell me how to do this


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#2 2006-10-30 03:44:18

luca-deltodesco
Member
Registered: 2006-05-05
Posts: 1,470

Re: circle

the equatin for a circle is

for yours this is

now, this is for a circle with x = y = 0

to translate a graph c units to the right, you have to take c away from x, similarly for y, so for you have

im not sure what it means by standard form, whether it wants it in that for, or in expanded form by


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#3 2006-10-30 03:54:04

unique
Member
Registered: 2006-10-04
Posts: 419

Re: circle

umm thanks
i guess they are asking for that....
standard form is  > x^2 + y^2 = r^2
so i think
it has to be
(x - 3)^2 + (y - 2)^2 = 5^2

and
x^2 + y^2 - 8 = 0 is equal to general form.
THANKS = )


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#4 2006-10-30 06:34:31

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

Re: circle

I'd say that (x-3)² + (y-2)² = 5² was the standard form.

If you did expand it out though, you'd get x² - 6x + y² - 4y - 12 = 0.


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#5 2006-10-30 08:37:25

luca-deltodesco
Member
Registered: 2006-05-05
Posts: 1,470

Re: circle

mathsyperson wrote:

I'd say that (x-3)² + (y-2)² = 5² was the standard form.

If you did expand it out though, you'd get x² - 6x + y² - 4y - 12 = 0.

yeh i know, i dont know where i got that thing from tongue but i was busy eating at the time, nevermind tongue


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