y^2=16x Graph the equation. Identify the focus, directrix, and axis of symmetry of the parabola.

Parabola is curve  graph such that each ordered pair (x,y) is equidistant distance to the fixed line (directrix) and fixed point (foci). We have "p" units  as distance of foci or directrix from the vertex. A parabola with vertex at the origin (0,0)  follow standard formula as:
a) x^2 =4py when parabola opens upward
b) x^2 =-4py when parabola opens  downward
c) y^2 =4px when parabola opens to the right 
d)  y^2 =-4px when parabola opens left.
The given equation y^2=16x resembles the standard formula y^2=4px .
 Thus, the parabola opens to the right and  we may solve for p using:
4p =16
(4p)/4 = 16/4
p =4
 When  parabola opens sideways, that  means the foci and vertex will have the same values of x . We follow the properties of the parabola that opens to right as:
vertex at point (h,k)
foci at point (p,k)
 directrix at x= k-p
axis of symmetry: y =k
endpoints of latus rectum: (p,2p) and (p, -2p)
 
Using vertex (0,0) , we have h =0 and k=0 .
Applying  k=0 and p=4 , we get the following properties:
a) foci at point ( 4, 0)
b) axis of symmetry: y=0 .
c) directrix at x= 0-4 or x=-4.
d) Endpoints of latus rectum: (4,2*4) and (4, -2*4) simplify to (4,8) and (4.-8) .
To graph the parabola, we connect the vertex with the endpoints of the latus rectum and extend it at both ends. Please see the attached file for the graph of  y^2=16x.