help would be appreciated if u can solve it all i will be very thankful and i would like some hints too

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- Apr 15th 2008, 06:03 PMcarlasaderhelp in this math project
help would be appreciated if u can solve it all i will be very thankful and i would like some hints too

- Apr 16th 2008, 12:20 AMMathnasium
What have you done so far? Where are you stuck? What formulas do you know about circles?

- Apr 16th 2008, 04:38 AMskystar
The equation of a circle is $\displaystyle (x-a)^2 + (y-b)^2 = r^2 $

where $\displaystyle (a,b) $ is the centre of the circle and r the radius. - Apr 16th 2008, 07:00 AMAryth
$\displaystyle x^2 + y^2 - 2x - 4y - 4 = 0$

$\displaystyle (x^2 - 2x) + (y^2 - 4y) = 4$

Complete the square for both:

$\displaystyle (x^2 - 2x + 1) + (y^2 - 4y + 4) = 9$

Now we factor:

$\displaystyle (x - 1)^2 + (y - 2)^2 = 3^2$

Therefore, r = 3 and the center is $\displaystyle (1, 2)$