(plotting on a graph) What is the formula...?

Question

Say I have a starting point (x = 5, y = 0) what is the formula that would create a circle around the center of the graph? What are some online references for these things? Wikipedia is awesome but I don't get the large part of the symbols they use (I only got as far as Alg. 1 and now regret it)

Answer 1

The general formula for a circle on a plane is
(x - x0)^2 + (y-y0)^2 = r^2,
where r is the radius, and ^2 means the square power.
In your case

(x-5)^2 + (y-0)^2 = R^2

In fact it is the expression of the Pythagoras theorem, as you can realize if you draw it.

I apologize for my band english.

Answer 2

(x-x0)^2+(y-y0)^2=a^2 is the general equation of a circle with center (x0,y0) and radius a.Your case gives only the centre and the general equation is (x-5)^2+(y-0)^2=a^2.