Questions: Find an equation, in terms of x and y, for the parabola conic whose graph is shown.
Transcript text: Find an equation, in terms of $x$ and $y$, for the parabola conic whose graph is shown.
Solution
Solution Steps
Step 1: Find the vertex
The vertex is the point on the parabola that is closest to the directrix. From the graph, the vertex is at $(-7, 0)$.
Step 2: Determine the orientation and the value of p
Since the parabola opens to the right and the directrix is vertical, the equation of the parabola is of the form $(y-k)^2 = 4p(x-h)$, where $(h,k)$ is the vertex. The vertex is $(-7, 0)$, so $h=-7$ and $k=0$. The directrix is $x = -11$. Since the parabola opens to the right, $p > 0$. The distance between the vertex and the directrix is $|h - (-11)| = |-7 + 11| = 4$. So, $p = 4$.
Step 3: Write the equation
Substitute the values of $h$, $k$, and $p$ into the equation $(y-k)^2 = 4p(x-h)$:
$(y-0)^2 = 4(4)(x-(-7))$
$y^2 = 16(x+7)$