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

neverforgetvivistee Group Title

can someone please help me in understanding graphing quadratic inequalities? look at this (answers are below) http://www.kutasoftware.com/FreeWorksheets/Alg1Worksheets/Graphing%20Quadratic%20Inequalities.pdf what does the solid/shaded line mean? Why is it shaded in and some are shaded out? I know how to get the coordinates by plugging in random x values, but I don't know about anything else.

  • 2 years ago
  • 2 years ago

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

    ok, in general, lets say you have some function in the form:\[y=f(x)\]and you have some inequality like:\[y>=4\]

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

    now, on the line \(y=f(x)\) you know the value of 'y' will EQUAL the value of 'f(x)', so we draw the curve for y=f(x) as a solid line to indicate that we need to include this region.

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

    so now we need to consider the line y=4. this will be a horizontal line which passes through y=4.

    • 2 years ago
  4. asnaseer Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    the horizontal line could intersect the curve at some points. e.g.: |dw:1322436287068:dw|

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

    now since our inequality is y>=4, we need to draw a solid line at the places where y=4.

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

    |dw:1322436426127:dw|

    • 2 years ago
  7. neverforgetvivistee Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    but what about the shaded region?

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

    sorry - my explanation went a bit hay wire above!

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

    what I should have said is lets say we have an inequality of the form y>=f(x)

    • 2 years ago
  10. neverforgetvivistee Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    lol it's okay take your time :)

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

    now, on the curve y=f(x), we know it satisfies the inequality - so we make the line solid

    • 2 years ago
  12. asnaseer Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    below the curve y=f(x) does NOT satisfy the inequality as there we have y<f(x)

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

    above the curve y=f(x) DOES satisfy the inequality, so we include that region by shading it in

    • 2 years ago
  14. neverforgetvivistee Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    for shading it in, how do you know it satisfies the inequality?

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

    |dw:1322436711384:dw|

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

    does the diagram make sense?

    • 2 years ago
  17. neverforgetvivistee Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    not really :(

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

    I have taken some point x=x1 (which is represented by the vertical line) where this vertical line crosses the curve y=f(x), we know y=f(x1) above that point of intersection, we know y>f(x1) below that point of intersection, we know y<f(x1)

    • 2 years ago
  19. neverforgetvivistee Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks :)

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

    np - sorry for the confusion at the beginning :-)

    • 2 years 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.