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toxicsugar22

  • 5 years ago

A doctor who is treated a heart patient wants to presicribe medication to lowere the patients blood pressure. The body's reaction to this medication is a function of the dose admininistered. If the patient takes x milliters of the medication, his blood pressure should decrease by r=f(x) points where f(x)=3x^2-1/3x^3 what values of x make sence for this function

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  1. toxicsugar22
    • 5 years ago
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    can u please help

  2. anonymous
    • 5 years ago
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    Hmm.. I would say find the min value, and would that give you the x value? that would make the most sense?

  3. toxicsugar22
    • 5 years ago
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    i got 9 and 0

  4. anonymous
    • 5 years ago
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    Okay, Im not sure I understand the question, sorry o.O Because at x=0 f(x) =0 as well. I believe. I don't think that helps in anyway. Sorry

  5. amistre64
    • 5 years ago
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    y = 3x^2-1 ------- this? 3x^3

  6. anonymous
    • 5 years ago
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    Ohhh. I didn't realize that was division. haha

  7. anonymous
    • 5 years ago
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    sorry, but i dont know enough to help you out

  8. toxicsugar22
    • 5 years ago
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    amitre is that the answer

  9. amistre64
    • 5 years ago
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    no thats a question about the problem :) is that the question at hand?

  10. anonymous
    • 5 years ago
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    Any value greater than 0 would make sense. right..

  11. toxicsugar22
    • 5 years ago
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    no its what values of x make sence for this function

  12. amistre64
    • 5 years ago
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    i think we want the maximum for f(x) so that his blood pressure reduces the most right?

  13. amistre64
    • 5 years ago
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    well, any values of x will work except for x=0

  14. anonymous
    • 5 years ago
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    i think we are looking for domain ?

  15. amistre64
    • 5 years ago
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    y = 3x^2-1 ------- is this the function we are working with? 3x^3

  16. toxicsugar22
    • 5 years ago
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    yes

  17. amistre64
    • 5 years ago
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    then lets see where this function is increaseing and decreasing for x

  18. anonymous
    • 5 years ago
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    Domain should be any value greater than 0. But I don't think its that simple.

  19. anonymous
    • 5 years ago
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    no amistre has got it

  20. anonymous
    • 5 years ago
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    nned function to be decreasing, or blood pressure is not decreasing

  21. amistre64
    • 5 years ago
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    the 1st derivative is: 3x^3(2x) - 9x^2(3x^2-1) -21x^4 +9x^2 ------------- 9x^6

  22. amistre64
    • 5 years ago
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    when the derivative is zero we get the highes and lowes of it;

  23. amistre64
    • 5 years ago
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    -3x^2 (7x^2 -3) = 0 when x = 0 and... sqrt(12)/14 = sqrt(3)/7 the only value here that makes sense is sqrt(3/7)

  24. amistre64
    • 5 years ago
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    now is it a high or a low :) or an inflection point is there an answer key for this to determine if we are doing it right :)

  25. toxicsugar22
    • 5 years ago
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    no ther isnt

  26. amistre64
    • 5 years ago
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    3x^2-1 ------- 3x^3 3 sqrt.3/7^2-1 -------------- 3 sqrt.3/7^3 -40/49 -------------- thats a negative number so id say its not going to be that point :) 9/49 (sqrt.3/7)

  27. amistre64
    • 5 years ago
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    lets see what the roots are if any to this equation when 3x^2-1 =0 3x^2 = 1 x^2 = 1/3 x = sqrt(1/3) = sqrt(3)/3 is a zero

  28. toxicsugar22
    • 5 years ago
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    so that is the answer

  29. amistre64
    • 5 years ago
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    0.577 is a root

  30. amistre64
    • 5 years ago
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    dunno; still running tests in my head :)

  31. toxicsugar22
    • 5 years ago
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    ok its okay

  32. toxicsugar22
    • 5 years ago
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    can u help me with one more that is not realted to this

  33. toxicsugar22
    • 5 years ago
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    pomblem

  34. toxicsugar22
    • 5 years ago
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    please

  35. amistre64
    • 5 years ago
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    http://www.wolframalpha.com/input/?i=%283x^2-1%29%2F%283x^3%29 is what we get for a graph

  36. amistre64
    • 5 years ago
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    its only effective after x=sqrt(3)/3 and peaks at x=1

  37. toxicsugar22
    • 5 years ago
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    ok but can u help with anot

  38. amistre64
    • 5 years ago
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    i can try :)

  39. toxicsugar22
    • 5 years ago
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    ok it poynomials are u good at that

  40. amistre64
    • 5 years ago
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    i can be at times lol

  41. toxicsugar22
    • 5 years ago
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    Find the first three terms in asending powers. (Do not compute the entire product) (1-2x^2-x^4)(4+x^2-2x^4)

  42. amistre64
    • 5 years ago
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    4 -7x^2 -8x^4

  43. toxicsugar22
    • 5 years ago
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    thats the answer

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