Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

mathhelp23

  • 2 years ago

solve 3x^2-5x-11=0 find the x intersepts of f(x)=3x^2-5x-11.

  • This Question is Closed
  1. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 4

    It's not complex

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

    \[D = b^2 - 4ac = (-5)^2 - 4(3)(-11) = 25 + 132 = 157\]

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

    \[x = \frac{\pm \sqrt{157} + 5}{6}\]

  4. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    any method ?

  5. mathhelp23
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thank you

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

    @Hero that's the answer i got,dat's why i called it a complex root

  7. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @krypton : square root of a negative number gives you a complex number solution

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

    any number is complex

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

    4 is complex 4i is complex 4+4i is complex

  10. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    4+0i

  11. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    why do we have real and complex sets then ?

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

    real numbers is a subset of the complex imaginary numbers is a subset of the complex

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

    all numbers are complex

  14. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    If a complex number has b = 0, then it is a real number and it lies on the real axis in the complex plane

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

    Definition of Complex: \[Complex =\{a+bi | a \in \mathbb{R} , b \in \mathbb{R}\}\]

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

    Define complex in words only without using mathematical notation.

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

    What a meant to say is that the discriminant yields a real number, not a complex number. The definition of a complex number is a + bi

  18. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The real line can be thought of as a part of the complex plane, and correspondingly, complex numbers include real numbers as a special case.

  19. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ... Special Case

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

    That's good to know. I'm not the one confused about it.

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

    Excuse me?

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

    I'm not confused either.

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

    I know you're not myininaya. I never said you were :P

  24. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    def : A complex number is neither purely real nor purely imaginary, but rather is a composite of the two ! Happy everyone ?

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

    Ok I guess I just understood you. sorry hero. :)

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

    misunderstood you* lol

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

    real numbers are complex imaginary numbers are complex real numbers+imaginary numbers are still complex

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

    she avoided using the word "pure" in her definitions.

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

    http://en.wikipedia.org/wiki/Complex_number

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

    So myininaya, which numbers are purely complex?

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

    I don't have a definition for "purely" complex numbers as I never heard of any set of numbers being defined at such sorry

  32. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    check out this book : An imaginary tale The Story of √-1 by Paul J. Nahim ( Professor Emeritus of Electrical Engineering at the University of New Hampshire )

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

    Guess there's no such thing as a pure complex number since it is a "mixture" of pure real and pure imaginary.

  34. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    4 is real 4+0i is complex

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

    4=4+0i

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

    4/2 is an integer just like 2 is

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

    because 4/2=2

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

    @jamesj @zarkon

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

    Why are you two reciting stuff you already know? Because I already know this stuff

  40. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1331351848500:dw|

  41. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    this is interesting ... LOL

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

    mathg8, I guess you really want krypton to understand

  43. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I just never heard this before ... so it is interesting ( not wrong or right ) just interesting ...

  44. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    real numbers are complex ( i meant this statement )

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

    lol intresting :)

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

    Krypton, I'm sure you enjoyed this

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

    lol yeah! alot,just woke up from sleep and logged in,only to find some argument in here.was fun :)

  48. mathg8
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes ... this was fun!

  49. 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.