A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Reimann Sum Continues.

  • This Question is Closed
  1. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ahhh, much better lol

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

    lol

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

    so i wrote down sum (-2+3i/n)(3/n)

  4. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    good, im reviewing some notes to bring me up to speed

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

    k can you also explain to me the point of what we are doing

  6. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the original equation: x^3 -3x can be split into easier parts x^3 and -3x we use the reimann sum formulas for (sum)x^3 and (sum)x to work these to completion

  7. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -3 lim(sum) x (3/n) is the easiest one to do, so lets start with that one :)

  8. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    we determined that f(x_i) = (-2+3i)/n right? so if the notes are correct, and I dont see any reason to dispute them, we multiply: (-2+3i)/n with 3/n

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

    (-2+3i/n)(3/n)

  10. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    (sum) (-6/n^2 + 9i/n^2)

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

    so -6/n+9i/n

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

    9i/n^2

  13. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    your right... I got lost there for a sec :)

  14. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    it says to split this one up into: (sum) -6/n+ (sum)9i/n^2

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

    why?

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

    adding rule?

  17. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah, I am suuming the adding rule :) it gets us to the (sum) i formula

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

    k i split is up as you said

  19. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    (9/n^2) (sum)i is... 9 n(n+1) ---- ------ n^2 2

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

    ok

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

    do we substitute that?

  22. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    9n(n+1) 9(n+1) ------- = ------ 2n^2 2n now work the other part: -6/n -> 1/n (sum) -6 = (1/n)(-6n) = -6 why? dunno, its just the example I got to go by :)

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

    k haha

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

    so we are at (-6+(9(n+1))/2

  25. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    9(n+1) ------ - 6 2n^2 -6n^2 9n 9 ----- + ---- + --- n^2 n^2 n^2

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

    oh you just lost me

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

    you just distributed?

  28. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    lost myself too, let me redo that last part :)

  29. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    9n+9 ------ - 6 2n -12n 9n 9 ----- + ---- + --- 2n 2n 2n might be better

  30. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -3 9 --- + --- = -3 as n-> inf 2 2n

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

    yup

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

    hold up what?

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

    lim as n goes to infinity sum =-3?

  34. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -3/2 ..... might be a better answer for the right side of our original equation....

  35. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I forgot the denominator of 2 :)

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

    oh because 9/2n goes to 0?

  37. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep, when a fraction gets bigg on the bottom what happens? 1 --------------------- becomes infinitly small 100000000000000000 it approaches zero

  38. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    .0000000000.....00000000000000001

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

    yea i know, sorry stupid question

  40. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    now if our f(a + i/x\) stuff was correct, then this is our right side part

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

    we are halfway done. Should we take the cube now

  42. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ummm...... we need to drag that -3 back over and multiply it I think :) -9/2

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

    cool 9/2

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

    not negative

  45. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -3(-3/2) = 9/2 that s right.... tell me im wrong :) i dont mind

  46. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    since its just: (sum) x^3 we can take our f^(x_1) and work it thru

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

    so (-2+3i/n)^3?

  48. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep, and I am assuming that that is correct :) otherwise we are getting good practice, but the wrong results :)

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

    at least we have the answer so we will know

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

    its 3/4 if you forgot

  51. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    whaaa!!????

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

    the entire answer is 3/4

  53. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah yeah...maybe..well see :)

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

    want me to distribute the cube?

  55. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep, cube it out so we can multiply our 3/n to it and apply the (sum) i^3 formula to it

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

    k give me a second

  57. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    gonna swig some coffee..... bad mormon....BAD!!

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

    k here it is non simplified: ( -8+12i/n+12i/n-18i^2/n^2+12i/n-18i^2/n^2-18i^2/n^2+27i^3/n^3)(3/n)

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

    simplified loll (-8+36i/n-54i^2/n^2+27i^3/n^3)(3/n)

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

    distributing the 3/n : (-24/n+108i/n^2-162i^2/n^3+81i^3/n^4)

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

    made me do all the dirty work ahhaah

  62. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thats what I get too :)

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

    sweet

  64. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    now lets divvy put the "i" factors

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

    now we take each summation?

  66. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yupp

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

    what does -24/n become

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

    do i just pull it out?

  69. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sum_-24/n +108/n^2 sum_i -162/n^3sum_i^2 +81/n^4 sum_i^3

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

    thats what i got

  71. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    muplitiply each one by the appropriate sum i^x formulas :)

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

    i have to go soon, are we almost done?

  73. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    not even close :) I can do it quicker on the paper probably.... how long you got?

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

    5 minutes

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

    can you attach the image after?

  76. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    aint gonna happen in 5 minutes :) I can work it out and post it here if youd like, might even figure out where I go wrong and learn something :)

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

    sounds good, that would be great. Sorry that i have to go.

  78. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    'sok, have fun....:)

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

    for that first one i got (108n^2+108)/2n^2

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

    ill come back later to see if you posted and if you are still online, i may ask you questions

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

    take care, you are a Hero for sure! haha

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

    Hey Im back, are you there? Its kinda late but did you finish?

  83. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Here it is

    1 Attachment
  84. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Wow amazing! You broke everything down

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

    You really helped me. I can't thank you enough

  86. 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.