Find the Directrix x-2=1/8(y+1)^2

$x - 2 = \frac{1}{8} {(y + 1)}^{2}$

Step 1

Isolate $x$ to the left side of the equation.

Simplify $\frac{1}{8} {(y + 1)}^{2}$ .

Rewrite.

$x - 2 = 0 + 0 + \frac{1}{8} {(y + 1)}^{2}$

Simplify by adding zeros.

$x - 2 = \frac{1}{8} {(y + 1)}^{2}$

Combine $\frac{1}{8}$ and ${(y + 1)}^{2}$ .

$x - 2 = \frac{{(y + 1)}^{2}}{8}$

Add $2$ to both sides of the equation.

$x = \frac{{(y + 1)}^{2}}{8} + 2$

Reorder terms.

$x = \frac{1}{8} \cdot {(y + 1)}^{2} + 2$

Step 2

Use the vertex form, $x = a {(y - k)}^{2} + h$ , to determine the values of $a$ , $h$ , and $k$ .

$a = \frac{1}{8}$

$h = 2$

$k = - 1$

Step 3

Find the vertex $(h, k)$ .

$(2, - 1)$

Step 4

Find $p$ , the distance from the vertex to the focus.

Find the distance from the vertex to a focus of the parabola by using the following formula.

$\frac{1}{4 a}$

Substitute the value of $a$ into the formula.

$\frac{1}{4 \cdot \frac{1}{8}}$

Simplify.

Combine $4$ and $\frac{1}{8}$ .

$\frac{1}{\frac{4}{8}}$

Cancel the common factor of $4$ and $8$ .

Factor $4$ out of $4$ .

$\frac{1}{\frac{4 (1)}{8}}$

Cancel the common factors.

Factor $4$ out of $8$ .

$\frac{1}{\frac{4 \cdot 1}{4 \cdot 2}}$

Cancel the common factor.

$\frac{1}{\frac{4 \cdot 1}{4 \cdot 2}}$

Rewrite the expression.

$\frac{1}{\frac{1}{2}}$

Multiply the numerator by the reciprocal of the denominator.

$1 \cdot 2$

Multiply $2$ by $1$ .

$2$

Step 5

Find the directrix.

The directrix of a parabola is the vertical line found by subtracting $p$ from the x-coordinate $h$ of the vertex if the parabola opens left or right.

$x = h - p$

Substitute the known values of $p$ and $h$ into the formula and simplify.

$x = 0$

Step 6

Find the Directrix x-2=1/8(y+1)^2

Related Questions

Support LCMGCF.com by disabling your adblocker.