Type the correct answer in each box. Use numerals instead of words. If necessary, use / for the fraction bar.

Given the directrix [tex]x=6[/tex] and the focus [tex](3, -5)[/tex], what is the vertex form of the equation of the parabola?

The vertex form of the equation is [tex]x = \square (y + \square)^2 + \square[/tex]



Answer :

To find the vertex form of the equation of the parabola given the focus [tex]\((3, -5)\)[/tex] and the directrix [tex]\(x = 6\)[/tex], follow these steps:

1. Identify the coordinates of the vertex [tex]\((h, k)\)[/tex]. Since the focus is [tex]\((3, -5)\)[/tex] and the directrix is [tex]\(x = 6\)[/tex], the vertex [tex]\((h, k)\)[/tex] lies midway between the focus and the directrix along the x-axis. Given these specific values, the vertex is [tex]\((3, -5)\)[/tex].

2. Determine the value of [tex]\(a\)[/tex] (the coefficient in the vertex form of the parabola equation). We use the formula [tex]\(a = \frac{1}{2(h - \text{directrix})}\)[/tex].
- [tex]\(h = 3\)[/tex]
- The directrix is [tex]\(6\)[/tex]

3. Compute the value of [tex]\(a\)[/tex]:
[tex]\[ a = \frac{1}{2(3 - 6)} = \frac{1}{2(-3)} = -\frac{1}{6} \][/tex]

4. Using the vertex form of the parabola equation with horizontal orientation:
[tex]\[ x = a(y - k)^2 + h \][/tex]

Substitute in the calculated values:
[tex]\[ x = -\frac{1}{6}(y - (-5))^2 + 3 \][/tex]

Simplify the expression inside the parentheses:
[tex]\[ x = -\frac{1}{6}(y + 5)^2 + 3 \][/tex]

Thus, the vertex form of the equation of the parabola is:
[tex]\[ x = -\frac{1}{6}(y + 5)^2 + 3 \][/tex]

Therefore, the correct answers to fill in the boxes are:
[tex]\[ x = \boxed{-\frac{1}{6}}(y + \boxed{5})^2 + \boxed{3} \][/tex]