A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Find the thex-coordinate of the vertex of the function given below. Y=(x-5)(x+3)

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

    The easiest way to determine the coordinates of the vertex is to write the parabola in vertex form.

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

    Meaning, \[y = a(x-h)^2+k\]

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

    You will have to expand that expression, then complete the square to get the vertex form.

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

    You will be able to read off the coordinates of the vertex (h, k) in the vertex form.

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

    What do I fill in?? For the problem?

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

    I listed the steps above. First, expand the expression. Then, complete the square.

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

    I don't know what that means I need to find the a,h,x,k

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

    Can you first expand the expression?

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

    What does that mean??

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

    (x+1)(x+2) = x^2 +3x + 2

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

    Expand the expression you have, like the example above.

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

    X^2-2x+3??

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

    Check your constant term again.

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

    5?

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

    You multiply (x-5) by (x+3) right? You should get -5*3 = -15.

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

    \[Y = (x-5)(x+3) = x^2-2x -15\]

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

    Do you agree?

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

    Yes

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

    Now, complete the square.

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

    This means you need to factorize the expression so that you force it to become a square (x+a)^2

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

    Do you know how to do that?

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

    no

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

    \[x^2-2x-15= (x-1)^2+k\]

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

    Do you follow what I did in that last step?

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

    Yes

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

    I was able to factorize it into (x-1)^2 because of the -2x term.

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

    But I will get a constant k.

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

    x^2+1+k?

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

    No, it's (x-1)^2+k

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

    Since you're only interested in the x-coordinate of the vertex, we are done. You don't need to solve for k in this question.

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

    Match the equation that we have, with the vertex formula above.

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

    What is the value of h?

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

    \[Y = a(x-h)^2+k =(x-1)^2+k\]

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

    so what do I do??

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

    Tell me the value of h.

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

    1?

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

    Correct, that's your x-coordinate.

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

    So the answer is 1

  39. 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.