In each of the Exercises 7 to 12, find the equation of the parabola that satisfies the given conditions: Vertex (0,0); focus (3,0)
= 12x
Explanation
The problem is solved by identifying the orientation of the parabola based on the position of the focus relative to the vertex, similar to the method used in Example 7 of the provided text. Since the vertex is at the origin and the focus lies on the x-axis, the parabola opens to the right, and its equation takes the standard form = 4ax. The value of 'a' is determined by the x-coordinate of the focus.
Solution Steps
Step 1: Identify the axis of the parabola. Since the vertex is at (0,0) and the focus is at (3,0), the focus lies on the x-axis. Therefore, the axis of the parabola is the x-axis.
Step 2: Determine the standard equation form. Since the focus is on the x-axis, the equation of the parabola is of the form = 4ax.
Step 3: Find the value of a. The coordinates of the focus for the parabola = 4ax are (a, 0). Given that the focus is (3, 0), comparing the coordinates gives a = 3.
Step 4: Formulate the equation. Substituting a = 3 into the standard form = 4ax, we get = 4(3)x, which simplifies to = 12x.