A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

I have my answer, just want to know if the discriminant is right.. y=x^2-5x-8 y=x 2 real solutions and a discriminant of 68.

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

    Would the discriminant be 68 or 17?

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

    @Hero

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

    Would you mind showing your work ?

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

    Yeah one second. I used the quadratic formula -b+-sqrt b^2 - 4ac/2a

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

    Do you know what kind of problem this is you're working on?

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

    Yes. I just want to know if my answer is correct

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

    It says "use the discriminant to find the number of solutions for each system."

  8. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\text{ the disciminant of } y=ax^2+bx+c \text{ is } b^2-4ac\]

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

    I know

  10. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then how did you get two solutions?

  11. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    discriminant will only be one number

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

    Because the answer it gives me is 6+-sqrt68/2 so I was wondering if the discriminant would be 68 or 17 once you simplify it.

  13. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so you didn't use the formula I wrote...

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

    I did!!

  15. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    b^2-4ac is going to give you the discriminant

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

    then how did you get + or - for the discriminant ?

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

    So it would be 68

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

    D=b^2-4ac and you have a=1 b=-5 c=-8 just plug in D=(-5)^2-4(1)(-8) this shouldn't give you 68

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

    Yes it should. You set the two equations equal to each other and get x^2-6x-8=0

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

    I see y=x^2-5x-8

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

    Why?

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

    Yes, but there is also the y=x

  23. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    because I thought the question was find the discriminant of y=x^2-5x-8? Is that not the question?

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

    So once you put them equal to each other

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

    Read the entire thing. It is a system. You know with the little {

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

    {y=x^2-5x-8 {y=x

  27. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh I think you are trying to see how many solutions to the system there are I didn't understand the question because the question wasn't actually given in the title

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

    Yes....

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

    I just wanted to know if the 68 would give me 2 real solutions

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

    Is all I was asking

  31. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes replace y with x in the first equation \[x=x^2-5x-8 \\ 0=x^2-6x-8 \\ a=1\\ b=-6 \\ c=-8 \\ D=b^2-4ac=(-6)^2-4(1)(-8)=36+32=68>0\] yes 68>0 so that means you have two solutions

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

    Thank you!

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

    Is what I was saying all along, but... :/

  34. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    It might be good to post the full question in the title next time. It would be very helpful.

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

    Alright, alright.. Thank you nontheless

  36. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Like determine the number of solutions to the system :p

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

    *nonetheless

  38. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and np

  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.