How do u graph y=x^2-4x+3 and find the vertex and symmetry?I just cant get this problem for some reason.Thanks?

Vertex is V ( -b/2a , f( -b/2a) ).....axis of symmetry x= -b/2a....just plug in the values and work it out ....answer V ( 2, -1 ) ...x=2 is axis of symmetry