# A tangent circle to a parabola

Calculus Level 4

Let $$y = \dfrac{x^2 } 4$$. A circle is tangent to this parabola at $$x_0 = 2$$, and also tangent to the $$y$$-axis. If $$r$$ is the radius of this circle, find $$\lfloor 100 r \rfloor$$.

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