Step 1: Write the formulae
Step 2: Find the radius of the first circle
In this case,
Since the circle passes through (-30,-16), then the distance between the center and (-30,-16) is the radius.
Let the radius be r. Then,
d=r, (x1,y1) = (0,0), and (x2,y2) = (-30,-16)
Therefore,
Thus
Therefore the radius of the new circle is 34 / 2 = 17
Step 3:
The new circle has radius 17 and center (0,0).
In this case,
r = 17
a = 0
b = 0
Therefore, the equation of the new circle is given by