Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Spartan_Of_Ares Group Title

i need help with domain

  • one year ago
  • one year ago

  • This Question is Closed
  1. Spartan_Of_Ares Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    • one year ago
    1 Attachment
  2. Spartan_Of_Ares Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    what is the domain of the graph?

    • one year ago
  3. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    The domain is the set of X values that this function can take on. So it appears we have a quadratic function, opening downward. The function that is graphed I think actually would look like this, \(f(x)=-(x-2)^2+3\) So the question is, what X values are you allowed to plug into that function? :O Hmmm..

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

    x ≥ 2 x ≤ −1

    • one year ago
  5. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    There is no square root, no dividing by x, no fractional exponent. There is nothing that we have to worry about when plugging values in for X. If we plug in -1 bajillion, we'll get a really big negative number for f(x), but it's still a real number.

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

    ?

    • one year ago
  7. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Since it's simply a quadratic, there are NO restrictions on the X term. The domain is ALL real numbers. :) You won't run into domain restrictions when you have nice polynomials like this - just simple powers of X.

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

    oh ok can you help me with this too? What is the range of the graph of y = −2x^2 − 8x − 7?

    • one year ago
  9. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So this one is similar to the last one. It will be a parabola opening DOWNWARD. Unfortunately, they didn't give it to us in vertex form. So let's convert it so it's a little easier to see what's going on.

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

    (-2,1)

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

    as the vertex maybe

    • one year ago
  12. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh man yer a lot faster at that than I am XD haha

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

    i use graphing tech

    • one year ago
  14. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh hah c: Well I wouldn't rely TOO MUCH on that, unless of course you're allowed to use it on a test ^^

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

    i am they give us graphing calculators

    • one year ago
  16. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh good good ^^

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

    :)}]

    • one year ago
  18. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So we have the vertex of our parabola at (-2,1) and it's opening downward (because of the negative sign on the x^2 term). So similar to the last problem, if we put in -2 bajillion for x, we'll get a really huge negative number for Y. But in this problem, if you graphed it, you may have noticed that we can't get any Y values larger than our vertex. The range represents the Y values the function can take on. So what would your range be? :O

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

    y ≤ −2?

    • one year ago
  20. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    The -2 represents the X value of our vertex. (-2,1).

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

    oh so y ≤ 1

    • one year ago
  22. zepdrix Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So Y can get as large as 1, and as negative as it wants? Yah that sounds right c: good job.

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

    ok thanks :)

    • one year ago
    • Attachments:

See more questions >>>

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.