Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

PaulinePar

  • 2 years ago

Can you guys identify the quadric surface using completing the squares of this equation. x^2+4y^2-6x+8y+4z=0? Thankyou :))

  • This Question is Open
  1. sirm3d
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    x^2 -6x +y^2 + 8y = -4z x^2-6x+9 + y^2+8y+16=-4z+25 (x-3)^2 + (y+4)^2=-4(z-25/4) it is a paraboloid of revolution, with vertex at (3,-4,25/4)

  2. PaulinePar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    where is 4y^2 in the first equation?

  3. sirm3d
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh, its 4y2. sorry.

  4. PaulinePar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its ok hehe .. but where did you get 9 and 16 in the 2nd equation?

  5. PaulinePar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sir how can i sketch the level curve z=k for the specified values of k. this is the equation z=x^2+y; k=-2, -1, 0, 1, 2

  6. sirm3d
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    completing squares, my dear. \[x^2+4y^2-6x+8y+4z=0\\(x^2-6x+9)+4(y^2+2y+1)=-4z+9+4\\(x-3)^2+4(y+1)^2=-4(z-\tfrac{13}{4})\\\frac{(x-3)^2}{4}+\frac{(y+1)^2}{1}=\frac{z-\tfrac{13}{4}}{-1}\]

  7. PaulinePar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you so much :)) nakalimutan ko na po kc hehehe .. Yung another question ko po help naman po.

  8. PaulinePar
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Sir thank you so much po sa lahat ng response nyo. sa lahat ng help nyo :))

  9. sirm3d
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    it is not a paraboloid of revolution as i said in my previous post. it is an elliptic paraboloid

  10. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.