Answer
Focus is: $(4,0)$ and directrix is: $x+4=0$
See the attached graph.
Work Step by Step
Standard form of a parabola is given as: $y^2=4px$ ...(1)
Formula to find focus is: $F(p,0)$ and formula to find directrix is: $x=-p$ or, $x+p=0$
As we are given that $y^2=16x \\ or, y^2=4(4)x$
Compare this form with the equation (1), we have: $p=4$
Thus, Focus is: $(4,0)$ and directrix is: $x+4=0$
See the attached graph.
