Write the equation of the circle centered at ( − 8 , − 4 ) that passes through ( 15 ,− 8 )?

1 Answer

(x+8)^2+(y+4)^2=545

Explanation:

Your circle has the equation of (x-x_c)^2 + (y-y_c)^2 = r^2
where x_c is the value of x of the center, and y_c is the value of y of the center and r is the radius. So here where the center is at (-8, -4), you circle is (x+8)^2+(y+4)^2=r^2
Time to find the radius (r):
Your circle passes through (15,-8) which means that (15+8)^2+(-8+4)^2=r^2
=> 23^2+(-4)^2=r^2
=> r^2=525
So finally, your circle is: (x+8)^2+(y+4)^2=545