Graphing circles problem help please!?

Question

I have to find the expression for the function whose graphs are the given curves...and this is what the problem reads

The top half of the circle (x-1)^2 + y^2 =1

I get that it is a circle with a radius of one and the vertex on (1,0), but how do i change the formula around so that it is talking just about the top half?

Answer 1

You could use a parametric equation:

x=1+cos t

y=sin t

0<t<pi