SOLUTION: Find the length of the latus rectum and the equation of the parabola with vertex at the origin, directrix x=-3 and focus (3, 0). Sketch the graph.
Algebra.Com
Question 1170335: Find the length of the latus rectum and the equation of the parabola with vertex at the origin, directrix x=-3 and focus (3, 0). Sketch the graph.
Answer by CPhill(1959) (Show Source): You can put this solution on YOUR website!
Let's solve this problem step-by-step.
**1. Determine the Orientation of the Parabola:**
* The vertex is at the origin (0, 0).
* The focus is at (3, 0).
* The directrix is x = -3.
* Since the focus is to the right of the vertex and the directrix is to the left, the parabola opens to the right.
**2. Determine the Value of 'p':**
* The distance between the vertex and the focus is 'p'.
* The distance between the vertex (0, 0) and the focus (3, 0) is 3.
* Therefore, p = 3.
**3. Find the Equation of the Parabola:**
* Since the parabola opens to the right and the vertex is at the origin, the equation is of the form:
$y^2 = 4px$
* Substitute p = 3 into the equation:
$y^2 = 4(3)x$
$y^2 = 12x$
**4. Find the Length of the Latus Rectum:**
* The length of the latus rectum is 4p.
* Since p = 3, the length of the latus rectum is 4(3) = 12.
**5. Sketch the Graph:**
* **Vertex:** (0, 0)
* **Focus:** (3, 0)
* **Directrix:** x = -3
* **Latus Rectum:** The latus rectum passes through the focus and is perpendicular to the axis of symmetry. Its endpoints are at a distance of 2p from the focus.
* Since 2p = 6, the endpoints of the latus rectum are at (3, 6) and (3, -6).
**Graph:**
```
^ y-axis
|
6 | * (3, 6)
| /
| /
| /
| /
0 +-----------+---> x-axis
| \
| \
| \
-6 | * (3, -6)
|
-3 | Directrix x=-3
```
**Summary:**
* **Length of the Latus Rectum:** 12
* **Equation of the Parabola:** $y^2 = 12x$
RELATED QUESTIONS
Graph and find the directrix, equation and latus rectum of a parabola with a vertex at... (answered by josgarithmetic)
Find the focus, vertex, length of latus rectum,and the equation of directrix of the... (answered by josgarithmetic,greenestamps)
Find the focus, directrix, and equation of the parabola with vertex at the origin, axis... (answered by CPhill)
Find the focus, vertex, directrix , axis, and latus rectum of the parabola, y2 =8x-8y (answered by lwsshak3)
Find the vertex, focus, length of latus rectum and the equation of directrix from the... (answered by josgarithmetic)
Given the equation of the parabola (x+2)^2=2(y-1), find the vertex, directrix, focus and... (answered by josgarithmetic)
Find the vertex, focus, length of latus rectum,and the equation of directrix of x^2 - 2x... (answered by josgarithmetic)
PARABOLA: what's the vertex, focus, directrix, latus rectum and graph of the... (answered by solver91311)
Find the vertex, focus, length of latus rectum,and the equation of directrix of y^2 - 4y... (answered by josgarithmetic,greenestamps)