Find the equation of a circle given the center and line tangent to the circle

The video tutorial explains how to write the equation of a circle given its center and the fact that it is tangent to the X axis. It covers the standard form of a circle's equation, the concept of tangency, and how to determine the radius by understanding the distance from the center to the X axis. The tutorial uses a step-by-step approach to ensure comprehension of these geometric concepts.

What is the center of the circle mentioned in the problem?

Describe the relationship between the center of the circle and the radius when the circle is tangent to the X axis.