Learn to graph a horizontal parabola & identify the focus & directrix

The video tutorial explains how to graph the parabola y^2 = 16x. It covers identifying the vertex at (0,0), determining the focus at (4,0), and finding the directrix at x = -4. The tutorial emphasizes understanding the relationship between the vertex, focus, and directrix to determine the parabola's orientation. The focus is calculated using the equation 4P = 16, resulting in P = 4, indicating the parabola opens to the right. The directrix is found by moving 4 units in the opposite direction from the vertex. The tutorial concludes by summarizing the steps to graph a parabola, focusing on the vertex, focus, and directrix.

Explain how to find the focus of the parabola.

What is the definition of the directrix in relation to the focus and vertex?