Finds out the center & radius of each of the following circles & sketch the graph of the circle.

a) x²+ y ² = 1

b) x²+ ( y - 3)²  = 4

Solution

In all of these all that we actuallyhave to do is compare the equation to the standard form and recognizes the radius & center.  Once that is done determine the four points talked about above and sketch in the circle.

x²+ y ²  = 1

 In this case it's just x & y squared by them. The only way which we could have it is to have both h & k be zero. Thus the center & radius is,

                                    center = (0, 0) radius =√1 = 1

Don't forget that the radius is the square root of the number on the other side of the equal sign. Following is a sketch of this circle.