# How do you write the standard form of the equation of the circle with the given the center (7,-3); tangent to the x-axis?

##### 1 Answer

#### Answer:

or

or

#### Explanation:

If the circle has a center at

then it has a radius of

The explicit standard circle equation for a circle with center at

which given the first version above

Some (but not all) teachers like to see this expanded to get rid of the double minus signs and express the squared radius as a single entity:

and still others are looking for the standard form of a general polynomial which is completely expanded with the right side as a series of terms in decreasing degree and the left side

(The third form above).