Question 985894
first write your equation in vertex form :{{{y=a(x-h)+k}}} where {{{h}}} and {{{k}}} are {{{x}}} and {{{y}}} coordinates of the vertex

{{{y=x^2-4x+4}}}......complete square; here you have

{{{y=(x-2)^2}}}=> {{{a=1}}},{{{h=2}}} and {{{k=0}}}

vertex is at:({{{2}}},{{{0}}})

{{{a>0}}}=> parabola opens upwards

then the focal distance {{{d1/4a}}} , in this case {{{a=1}}} and {{{d=1/4}}}

focus | ({{{2}}}, {{{1/4}}})
semi-axis length | {{{1/4}}}
directrix | {{{y = -1/4}}}

{{{drawing( 600, 600, -5, 5, -5, 5,
circle(2,1/4,.071),locate(2,.70,F(2,1/4)),locate(2,-.35,directrix),
 graph( 600, 600, -5, 5, -5, 5, x^2-4x+4,-1/4,-1/4)) }}}