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

Swageraid32 Group Title

@tcarroll010 can you help me with 4 and 5 of this....

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    • 2 years ago
    1 Attachment
  2. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    those are my last two please........... ;/

    • 2 years ago
  3. jim_thompson5910 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    # 4 D = b^2 - 4ac D = (1)^2 - 4(0.05)(1) D = ???

    • 2 years ago
  4. shyLove98 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I'm sorry. I don't know any of this. I tried. I'm really really really sorry. :(((

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

    if you have a the equation of a parabola in standard form: y= ax^2 + bx +c you match up the coefficients of your equation with a, b, and c then use those numbers for a, b, and c in the formula discriminant= b^2 -4ac jim_t already did most of the work for you.

    • 2 years ago
  6. Beautiful_Lier96 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    im confused

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

    y= 0.05 x^2 + 1x + 1 is your equation

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

    I think phi has got you covered

    • 2 years ago
  9. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    hmmm....???

    • 2 years ago
  10. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    you mean that is how i do the quadratic part??

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

    we are doing question 4. They want to know the discriminant (of your quadratic equation) I assume they mean the equation they give in question 1 To find the discriminant we first do step 1: first step: pattern match y= 0.05 x^2 + 1x + 1 y= a x^2 +b x + c what is a,b, and c?

    • 2 years ago
  12. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i have that part i need number 5

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

    what did you get for a, b and c

    • 2 years ago
  14. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    wait what?? like for the explanation part??

    • 2 years ago
  15. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    D = (1)^2 - 4(0.05)(1)

    • 2 years ago
  16. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ??

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

    I see you copied Jim's answer To find the discriminant we first do step 1: first step: pattern match y= 0.05 x^2 + 1x + 1 y= a x^2 +b x + c what is a,b, and c?

    • 2 years ago
  18. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    a=0.05 b=1x c=1

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

    almost, b is just 1 (we only want the numbers. a= 0.05, b=1 , c=1 step 2: replace the letters a, b, and c in b^2 - 4ab with the numbers you just found (remember b^2 is short for b*b 4ab is short for 4*a*b * means multiply

    • 2 years ago
  20. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    1^2-4(0.05)(1)

    • 2 years ago
  21. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    .8

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

    now what is 1^2 ? 1*1 = 1 4*0.05 is 0.2 0.2*1 is 0.2 so 1- .2 = 0.8 the discriminant is 0.8

    • 2 years ago
  23. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok i get that thanks for actually working with me and not giving just the answer :D

    • 2 years ago
  24. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    so could you assist me in #5 as well??

    • 2 years ago
  25. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @phi ??

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

    For 5, the quadratic formula is \[ x=\frac{−b±\sqrt{b^2−4ac}}{2a}\] notice that the stuff inside the square root is the "discriminant", which you already figured out is 0.8 you also know what a, b and c are. So replace the letters with numbers what do you get?

    • 2 years ago
  27. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    a=0.05, b=1, c=1 \[x=\frac{−1±\sqrt{1^2- 4\times0.05\times1}}{2\times0.05}\]

    • 2 years ago
  28. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @phi ?? like that??

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

    I just noticed that the equation you have from question 1 should be y= 0.05x^2 -x +1 notice that b is -1 (not +1) this changes your answers (gack!)

    • 2 years ago
  30. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    yea i know it is a typo the graph is wrong

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

    if we use b= -1 we get \[x= \frac{1 ± \sqrt{0.8}}{0.1}= 10±\sqrt{80} = 10± 4\sqrt{5} \] you get two answers x= 10+4sqrt(5) and x= 10-4sqrt(5) these are where the graph crosses the x-axis

    • 2 years ago
  32. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    wait i am confused

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

    which part?

    • 2 years ago
  34. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    the part like so i need to switch it to a -1?

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

    It's your call. The question says find the equation, from the graph. Did you find the equation from the graph? If so, you got it wrong?

    • 2 years ago
  36. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    o wow no i used the graph that was provided on the graph ;( that means i have to go back and do this all again :/

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

    Q1 general equation is y=0.05 x^2 -x +1 vertex form is 0.05(x-10)^2 - 4

    • 2 years ago
  38. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    so that means its this? y= 0.05 x^2 -1x + 1

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

    in Q2, the -10 become +10 so that means its this? y= 0.05 x^2 -1x + 1 Yes

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

    in Q2, the domain are all valid x's in this case, -inf to +infinity

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

    in Q2, the range is all y values. from the graph, you see y is always bigger than -4

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

    in Q3, your x-intercepts should be positive

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

    in Q4, b is -1 not +1, but it won't change the discriminant calculation.

    • 2 years ago
  44. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    ok thanks for all that :D

    • 2 years ago
  45. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    i do need your help again though i mean how are you supposed to find the domain and range? @phi

    • 2 years ago
  46. Swageraid32 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    @phi

    • 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.