http://www.dabbleboard.com/draw?b=Guest1181936&i=0&c=e3a384ec65dd8ae82173aaff291709153279e961then the graph is what I've drawn, by editing yours ( the general idea...)
looking at the equation.. the degree of equation is 2.. that is the equation is bound to have 2 roots.
now.. when x=2 the equation = 0; that means that 2 is a root... and the equation is (x-2)^2 that is there are two roots both x=2,2 and while they are two roots they are not distinct.
the shape of a quadratic is always a parabola..
the nature of roots can be found by finding sqrt(b^2 - 4ac) of a quadratic equation of form
ax^2 + bx +c = 0.
also the direction of the curve can be identified by the sign of coefficient of x^2..
since it is the highest power of x.. it is bound to decide the direction of the curve..