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Swageraid32

  • 3 years ago

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

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  1. Swageraid32
    • 3 years ago
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  2. Swageraid32
    • 3 years ago
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    those are my last two please........... ;/

  3. jim_thompson5910
    • 3 years ago
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    # 4 D = b^2 - 4ac D = (1)^2 - 4(0.05)(1) D = ???

  4. shyLove98
    • 3 years ago
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    I'm sorry. I don't know any of this. I tried. I'm really really really sorry. :(((

  5. phi
    • 3 years ago
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    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.

  6. Beautiful_Lier96
    • 3 years ago
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    im confused

  7. phi
    • 3 years ago
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    y= 0.05 x^2 + 1x + 1 is your equation

  8. evergirl
    • 3 years ago
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    I think phi has got you covered

  9. Swageraid32
    • 3 years ago
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    hmmm....???

  10. Swageraid32
    • 3 years ago
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    you mean that is how i do the quadratic part??

  11. phi
    • 3 years ago
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    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?

  12. Swageraid32
    • 3 years ago
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    i have that part i need number 5

  13. phi
    • 3 years ago
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    what did you get for a, b and c

  14. Swageraid32
    • 3 years ago
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    wait what?? like for the explanation part??

  15. Swageraid32
    • 3 years ago
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    D = (1)^2 - 4(0.05)(1)

  16. Swageraid32
    • 3 years ago
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    ??

  17. phi
    • 3 years ago
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    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?

  18. Swageraid32
    • 3 years ago
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    a=0.05 b=1x c=1

  19. phi
    • 3 years ago
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    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

  20. Swageraid32
    • 3 years ago
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    1^2-4(0.05)(1)

  21. Swageraid32
    • 3 years ago
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    .8

  22. phi
    • 3 years ago
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    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

  23. Swageraid32
    • 3 years ago
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    ok i get that thanks for actually working with me and not giving just the answer :D

  24. Swageraid32
    • 3 years ago
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    so could you assist me in #5 as well??

  25. Swageraid32
    • 3 years ago
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    @phi ??

  26. phi
    • 3 years ago
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    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?

  27. Swageraid32
    • 3 years ago
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    a=0.05, b=1, c=1 \[x=\frac{−1±\sqrt{1^2- 4\times0.05\times1}}{2\times0.05}\]

  28. Swageraid32
    • 3 years ago
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    @phi ?? like that??

  29. phi
    • 3 years ago
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    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!)

  30. Swageraid32
    • 3 years ago
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    yea i know it is a typo the graph is wrong

  31. phi
    • 3 years ago
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    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

  32. Swageraid32
    • 3 years ago
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    wait i am confused

  33. phi
    • 3 years ago
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    which part?

  34. Swageraid32
    • 3 years ago
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    the part like so i need to switch it to a -1?

  35. phi
    • 3 years ago
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    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?

  36. Swageraid32
    • 3 years ago
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    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 :/

  37. phi
    • 3 years ago
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    Q1 general equation is y=0.05 x^2 -x +1 vertex form is 0.05(x-10)^2 - 4

  38. Swageraid32
    • 3 years ago
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    so that means its this? y= 0.05 x^2 -1x + 1

  39. phi
    • 3 years ago
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    in Q2, the -10 become +10 so that means its this? y= 0.05 x^2 -1x + 1 Yes

  40. phi
    • 3 years ago
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    in Q2, the domain are all valid x's in this case, -inf to +infinity

  41. phi
    • 3 years ago
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    in Q2, the range is all y values. from the graph, you see y is always bigger than -4

  42. phi
    • 3 years ago
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    in Q3, your x-intercepts should be positive

  43. phi
    • 3 years ago
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    in Q4, b is -1 not +1, but it won't change the discriminant calculation.

  44. Swageraid32
    • 3 years ago
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    ok thanks for all that :D

  45. Swageraid32
    • 3 years ago
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    i do need your help again though i mean how are you supposed to find the domain and range? @phi

  46. Swageraid32
    • 3 years ago
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    @phi

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