Question
upstudy study bank question image url

equation in vertex form for the parabola with focus \( \left(-4,-\frac{19}{4}\right) \) and directrix \( y=\frac{11}{4} \) any fractions.

Ask by John Dickson. in the United States
Feb 03,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

The equation of the parabola in vertex form is \( y = -\frac{1}{15}(x + 4)^2 - 1 \).

Solution

To find the equation of the parabola in vertex form given the focus and directrix, follow these steps: ### 1. **Identify the Vertex:** The vertex of the parabola is the midpoint between the focus and the directrix. - **Focus:** \((-4, -\frac{19}{4})\) - **Directrix:** \(y = \frac{11}{4}\) Calculate the y-coordinate of the vertex: \[ \text{Vertex } y = \frac{-\frac{19}{4} + \frac{11}{4}}{2} = \frac{-\frac{8}{4}}{2} = -1 \] So, the vertex is at \((-4, -1)\). ### 2. **Determine the Direction:** Since the focus is below the directrix, the parabola opens **downward**. ### 3. **Calculate the Value of \(p\):** \(p\) is the distance from the vertex to the focus: \[ p = -\frac{15}{4} \] (The negative sign indicates the downward direction.) ### 4. **Find the Value of \(a\):** The standard vertex form of a parabola is: \[ y = a(x - h)^2 + k \] where \((h, k)\) is the vertex. \[ a = \frac{1}{4p} = \frac{1}{4 \times -\frac{15}{4}} = -\frac{1}{15} \] ### 5. **Write the Equation in Vertex Form:** Plugging in the values of \(a\), \(h\), and \(k\): \[ y = -\frac{1}{15}(x + 4)^2 - 1 \] ### **Final Answer:** \[ y = -\frac{1}{15}(x + 4)^2 - 1 \]

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Bonus Knowledge

To find the equation in vertex form for the given parabola, we start by identifying the vertex, which lies midway between the focus and the directrix. The vertex \( V \) can be calculated as follows: The y-coordinate of the vertex is the average of the y-coordinates of the focus and directrix: \[ y_V = \frac{-\frac{19}{4} + \frac{11}{4}}{2} = \frac{-8}{4} = -2 \] The x-coordinate of the vertex is the same as that of the focus, hence \( x_V = -4 \). So, the vertex is at \( V(-4, -2) \). The distance \( p \) from the vertex to the focus (or directrix) is: \[ p = -2 - (-\frac{19}{4}) = -2 + \frac{19}{4} = \frac{11}{4} \] Since the focus is below the vertex, the parabola opens downward. The vertex form of a parabola that opens downwards is expressed as: \[ y = -\frac{1}{4p}(x - h)^2 + k \] Substituting \( h = -4 \), \( k = -2 \), and \( p = \frac{11}{4} \) gives: \[ y = -\frac{1}{11}(x + 4)^2 - 2 \] That’s the vertex form of the parabola! Now it’s time to admire your work—parabolas have so much elegance. If you want to explore this topic further, consider studying the conic sections. They’re not just parabolas; you’ll also discover ellipses and hyperbolas! Each has its own unique properties and equations. You can find many engaging resources online or at your local library to dig deeper into the world of curves and geometric shapes. Keep spiraling down the math rabbit hole—it's full of surprises!

Related Questions

Latest Pre Algebra Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy