Review the Equation of a circle
The circle is created by the idea of having a fixed point, the center A, and another point, P(x, y) rotating around A with a distance r, radius.
a. Use the distance formula to represent the distance, r, in terms of A(0,0) and P(x,y).
b) If you square the equation above, you obtain an equation of the circle with center A and radius r.
Apply the text above on part(a) and write down the equation of the circle:
If A is not on the origin then A has coordinates A(h,k) and P(x,y). Then you obtain the general form of an equation of a circle.
c. What is the general form of the equation of the circle having center A(h,k)?
d. What is the value of r in terms of the coordinates of A(h, k)and P(x, y), where A is the center of the circle?