A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Using the following equation, find the center and radius of the circle. You must show all work and calculations to receive credit. x2 − 4x + y2 + 8y = −4

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

    suppose i don't want to show all my work? can i get partial credit?

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

    I don't want the answer. I want you to help me do it

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

    the idea is to complete the square twice, once for \[x^2-4x\] and again for \[y^2+8y\]

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

    4x^2 and 8y^2

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

    oh no

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

    have you learned how to "complete the square"?

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

    no

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

    then you can't do this problem

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

    oh

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

    i will show you how to complete the square for \(x^2-4x\) what is half of 4?

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

    2

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

    right so we start with \[x^2-4x+y^2+8x=-4\]and turn it in to \[(x-2)^2+y^2+8y=-4+2^2\]

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

    or\[(x-2)^2+y^2+8y=0\] now we repeat with \(y^2+8y\)

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

    what is half of 8?

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

    4

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

    so we go right to \[(x-2)^2+(y+4)^2=0+4^2\]

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

    or just \[(x-2)^2+(y+4)^2=16\] now your circle is in standard form and you can read off the center and radius from the equation

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

    ok thank you

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

    yw

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

    I'm so sorry. when I look at numbers, they get mixed up in my head and I don't understand math in the first place.

  21. 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.