Examples
(0,-4)(0,−4) , r=6r=6
Step 1
The standard form of a circle is x2x2 plus y2y2 equals the radius squared r2r2. The horizontal hh and vertical kk translations represent the center of the circle. The formula is derived from the distance formula where the distance between the center and every point on the circle is equal to the length of the radius.
(x-h)2+(y-k)2=r2(x−h)2+(y−k)2=r2
Step 2
Fill in the values of hh and kk which represent the center of the circle.
(x-0)2+(y+4)2=r2(x−0)2+(y+4)2=r2
Step 3
Fill in the value of rr which represents the radius of the circle.
(x-0)2+(y+4)2=(6)2(x−0)2+(y+4)2=(6)2
Step 4
Step 4.1
Simplify the left side of the equation.
Step 4.1.1
Multiply -1−1 by 00.
(x+0)2+(y+4)2=(6)2(x+0)2+(y+4)2=(6)2
Step 4.1.2
Add xx and 00.
x2+(y+4)2=(6)2x2+(y+4)2=(6)2
Step 4.1.3
Remove parentheses.
x2+(y+4)2=62x2+(y+4)2=62
x2+(y+4)2=62x2+(y+4)2=62
Step 4.2
Raise 66 to the power of 22.
x2+(y+4)2=36x2+(y+4)2=36
x2+(y+4)2=36
Step 5