Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

shivraj

  • 2 years ago

f(x)=(-3x^2)+13x-11

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

    What are you supposed to do with this? Graph it?

  2. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    no

  3. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    What then? You haven't posted the directions.

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

    Find roots?

  5. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    how to complete a square

  6. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yep

  7. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Hint: Since y = f(x), rewrite it like this: \(y = -3x^2 + 3x - 11\) Next add 11 to both sides, then divide divide both sides by -3 to get: \(\frac{y + 11}{-3} = x^2 - x\) Now add \(\frac{1}{16}\) to both sides to get: \(\frac{y + 11}{-3} + \frac{1}{16} = x^2 - x + \frac{1}{16}\) Once you have finished reducing, you should have a new expression for y

  8. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    is that the answer

  9. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ?

  10. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The final result I get comes out to \(y = -\large\frac{48(x-\frac{1}{4}^2) - 3}{16} - 11\)

  11. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    But that hasn't been simplified

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

    How is that better than what he wrote originally?

  13. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Because it said to complete the square

  14. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Once you complete the square, you have to put it back in the form y =

  15. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    But let me fix one minor mistake

  16. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(y = -\large\frac{48(x-\frac{1}{4})^2 - 3}{16} - 11\)

  17. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok

  18. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Ideally, I think you would want to express that as just one fraction.

  19. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes

  20. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Well, I did most of the work for you. You can finish the rest.

  21. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Also, you might want to change y back to f(x)

  22. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok sure

  23. goformit100
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  24. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(f(x) = -\large3(x-\frac{1}{4})^2 - \frac{179}{16}\)

  25. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    THANKS

  26. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    hero

  27. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I must have made a calculation mistake because here's wolfram alpha's result: http://www.wolframalpha.com/input/?i=complete%20square%20(%5B%2F%2Fquantity%3A-3%2F%2F%5D)x%5E2%2B(%5B%2F%2Fquantity%3A13%2F%2F%5D)x%2B(%5B%2F%2Fquantity%3A-11%2F%2F%5D)

  28. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yeah, I see where I went wrong. I added 1/16 to both sides instead of adding 1/4 to both sides

  29. shivraj
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok

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

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

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.