Question 470789
{{{f(x)=2(x-2)^2}}} is in the form {{{f(x)=a(x-h)^2+k}}} where (h,k) is the vertex and x=h is the line of symmetry. 



So because h=2 and k=0, the vertex is (2,0) and the line of symmetry is x=2.



Here's a graph to confirm this:



{{{ graph( 500, 500, -10, 10, -10, 10, 2(x-2)^2) }}}