Math Problem Statement
I. Graphing Parabolas: Graph the following equations in a rectangular coordinate plane. Then, identify the required properties being asked in each item.
- 3y^2 - 18y + 12x + 3 = 0 Standard Form: Opening: Vertex: Distance between the vertex and focus: Focus: Equation of Axis of Symmetry: Length of Lactus Rectum: Endpoints of Latus Rectum: Equation of Directrix:
Solution
To solve the given problem and extract the properties of the parabola, we will start by rewriting the equation in a standard form and then derive each required property step by step.
The given equation is:
Step 1: Rewrite in Standard Form
We begin by isolating the terms involving and , focusing on making the quadratic term in appear as part of a perfect square.
Move to the other side: Factor out the 3 from the terms on the left-hand side: Complete the square inside the parentheses. To complete the square, take half of the coefficient of , square it, and add and subtract the same value inside the equation. Here, half of is , and .
Add and subtract 9 inside the parentheses: Simplify this: Now move to the right-hand side: Finally, divide through by 3 to get the equation into standard form: This is the equation of a parabola in standard form , which opens horizontally.
Step 2: Identify Properties
-
Standard Form:
-
Opening:
Since the coefficient of is negative, the parabola opens left. -
Vertex:
The vertex is , which corresponds to . -
Distance between the vertex and focus (p):
From the standard form, , so .
The distance between the vertex and the focus is 1 unit. -
Focus:
The focus lies 1 unit to the left of the vertex, as the parabola opens left.
So, the focus is at . -
Equation of Axis of Symmetry:
The axis of symmetry is the horizontal line passing through the vertex.
The equation is . -
Length of Latus Rectum:
The length of the latus rectum is units. -
Endpoints of Latus Rectum:
The endpoints of the latus rectum are 2 units above and 2 units below the focus (since the length is 4 units and is symmetric about the focus).
The endpoints are and . -
Equation of Directrix:
The directrix is a vertical line located unit to the right of the vertex, at .
The equation of the directrix is .
Summary of Properties:
- Standard Form:
- Opening: Left
- Vertex:
- Distance between Vertex and Focus: 1 unit
- Focus:
- Equation of Axis of Symmetry:
- Length of Latus Rectum: 4 units
- Endpoints of Latus Rectum: and
- Equation of Directrix:
Would you like any further clarification or details?
Related Questions:
- How do we find the equation of a parabola if given its focus and directrix?
- How does the direction of the parabola's opening change with the coefficient of or ?
- What is the significance of the latus rectum in parabola geometry?
- How can we determine the focal distance in more complex conic sections like ellipses and hyperbolas?
- How does completing the square help in deriving the standard form of a conic?
Tip:
When graphing a parabola, always start by identifying the vertex, as it serves as the foundation for determining the focus, directrix, and other key features.
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Math Problem Analysis
Mathematical Concepts
Conic Sections
Parabolas
Quadratic Equations
Graphing
Formulas
Standard form of a parabola: (y - k)^2 = 4p(x - h)
Formula for completing the square: (b/2)^2
Distance formula for vertex and focus: p
Theorems
Parabola Equation Theorem
Axis of Symmetry Theorem
Latus Rectum Property of Parabolas
Suitable Grade Level
Grades 10-12