Equazione del tipo

\left(x-p \right)^2+ \left(y-q \right)^2=r^2

\left(x-3\right)^2+ \left(y-1\right)^2=0

r = 1 (slider from 0 to 5, step 0.5)
p = 0 (slider from -3 to 3, step 0.1)
q = 0 (slider from -3 to 3, step 0.1)
O = (0, 0)
C: (p, q)
d = Circle(C, r)
testo2: "" + d + ""
g(x, y) = x^(2) + y^(2)
testo5: "C\left( " + (LaTeX[p]) + ", " + (LaTeX[q]) + "  \right) "
testo3: "r=" + (LaTeX[r]) + ""