Find the focus and directrix of the parabola with the given equation. Then graph the parabola.
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
8. Conic Sections
Parabolas
Problem 13
Textbook Question
Find the focus and directrix of the parabola with the given equation. Then graph the parabola. y2 - 6x = 0
Verified step by step guidance1
Rewrite the given equation \(y^2 - 6x = 0\) in the standard form of a parabola. Start by isolating the \(x\) term: \(y^2 = 6x\).
Recognize that the equation \(y^2 = 4px\) represents a parabola that opens to the right with vertex at the origin \((0,0)\). Here, \$4p = 6\(, so solve for \)p\( by dividing both sides by 4: \)p = \frac{6}{4} = \frac{3}{2}$.
Identify the focus of the parabola. Since the parabola opens to the right, the focus is located at \((p, 0)\), which means the focus is at \((\frac{3}{2}, 0)\).
Find the equation of the directrix. For a parabola opening to the right, the directrix is a vertical line given by \(x = -p\). Substitute \(p = \frac{3}{2}\) to get the directrix: \(x = -\frac{3}{2}\).
To graph the parabola, plot the vertex at the origin \((0,0)\), the focus at \((\frac{3}{2}, 0)\), and draw the directrix line \(x = -\frac{3}{2}\). Sketch the parabola opening to the right, equidistant from the focus and directrix.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
2mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Standard Form of a Parabola
A parabola can be expressed in standard form to identify its geometric properties easily. For a parabola that opens horizontally, the form is (y - k)^2 = 4p(x - h), where (h, k) is the vertex and p determines the distance to the focus and directrix. Rewriting the given equation into this form helps locate these features.
Recommended video:
Parabolas as Conic Sections
Focus and Directrix of a Parabola
The focus is a fixed point inside the parabola, and the directrix is a line outside it, both equidistant from any point on the curve. For the form (y - k)^2 = 4p(x - h), the focus is at (h + p, k) and the directrix is the vertical line x = h - p. Understanding these definitions is key to finding their coordinates.
Recommended video:
Horizontal Parabolas
Graphing a Parabola
Graphing involves plotting the vertex, focus, and directrix, then sketching the curve that is equidistant from the focus and directrix. Knowing the orientation (horizontal or vertical) and the value of p helps determine the shape and width of the parabola. This visual representation aids in understanding the parabola’s properties.
Recommended video:
Horizontal Parabolas
Watch next
Master Parabolas as Conic Sections with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Textbook Question
545
views
