A curve \(C\) has equation \(y=\frac{1}{\sqrt{4ax-{{x}^{2}}}}\), where \(a > 0\).
Sketch \(C\) and give the equations of any asymptotes, in terms of \(a\) where appropriate.[4]
Find the smallest possible value of \(y\) in terms of \(a\).[1]
Describe the transformation that maps the graph of \(C\) onto the graph of \(y=\frac{1}{\sqrt{4{{a}^{2}}-{{x}^{2}}}}\).[3]