Question

Write the equation of the circle with center (-2, -5) and containing the point (-10, -20). Use the ^ key for the exponents. Write your answer as the example: (x+7)^2+(y-8)^2=100

Answer 1

the equation of the circle is \[(x-h)^2+(y-k)^2=r^2\] where:
(h,k) Center and r the radio
replace the center and you will have:
\[(x+2)^2+(y+5)^2=r^2\]
Now, you need find the radio so you have to use the points given. Replace the points and you have the radio

Answer 2

how to find their distance ? well \(\bf \textit{distance between 2 points}\\ \quad \\
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
&(-2\quad ,&-5)\quad &(-10\quad ,&-20)
\end{array}\qquad
d = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}\)

Answer 3

http://www.mathwarehouse.com/geometry/circle/images/equation-of-circle/general-formula-equation-of-circle.png

Answer 4

ok... i'm still confused no offence to any of you.

Answer 5

(x−h)^2+(y−k)^2=r2



(x−4)^2+(y+4)^2=180




How did I get the radius? Well, I used the distance formula: check Jdoe001's work .

The actual distance is \[\sqrt{180}\] or ~13.4

13.4^2=?

It's about 180.