Help please
The center of a circle is at (-5 , 1) and it has a radius of 9. What is the equation of the circle?
A.(x-5)^2+(y+1)^2= 81
B.(x-5)^2+(y+1)^2= 3
C.(x+5)^2+(y-1)^2= 81
D.(x+5)^2+(y-1)^2= 3
(x - a)^2 + (y-b)^2 = r^2
for circle of radius r and center at (a,b)
so this is c?
yes
thank you, Damon :)
You are welcome.
To find the equation of a circle, you can use the standard form equation: (x - h)^2 + (y - k)^2 = r^2, where (h, k) represents the center coordinates and r represents the radius.
In this case, the center of the circle is (-5, 1) and the radius is 9.
Substituting these values into the standard form equation, we get:
(x - (-5))^2 + (y - 1)^2 = 9^2
(x + 5)^2 + (y - 1)^2 = 81
So the correct equation of the circle is option C., (x + 5)^2 + (y - 1)^2 = 81.