A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

nosnip

  • one year ago

how to factorise and solve -x^2 - 8

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    8 isn't a perfect square, so that can't be factored without using radicals. As for solving it, is that equal to something?

  2. nosnip
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    that's what I thought but I've got to draw it as a graph

  3. nosnip
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    there's y= (x-2)(x+2)(x+2) and y= -x^2 -8

  4. nosnip
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I've only got to sketch it but I need the x intercept I think

  5. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so you need to sketch both of those and find the solution/intersection point?

  6. nosnip
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yep

  7. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok. for the first one you can use the x-intercepts. The second one, doesn't have x-intercepts. You can draw it using transformations. Reflect the parabola over the x-axis and shift it down 8.|dw:1443290058687:dw|

  8. nosnip
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ooh I see yes that's clever!

  9. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    :) You can solve this algebraically as well \((x-2)(x+2)(x+2)=-x^2-8\) \((x^2-4)(x+2)=-x^2-8\) \(x^3+2x^2-4x-8=-x^2-8\) \(x^3+3x^2-4x=0\)

  10. nosnip
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay thankyo uvery much

  11. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    you're welcome

  12. 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.