Solution for Problem 2.4.1

Find the equation in general form of a circle with the center at (0,0) and radius of  6.

Solve

Step

r = 6 and (h, k) = (0, 0) (0,0) is the origin 
(x - h)2 + (y - k)2 = r2  Use Standard Equation form
(x - 0)2 + (y - 0)2 = 62  Simplify 
x2 + y2  = 36 Set equal to zero
x2 + y2  - 36 = 0 General Form