Results 1 to 7 of 7

Math Help - summations

  1. #1
    Member
    Joined
    Nov 2008
    From
    MD
    Posts
    165

    Exclamation summations

    sorry i have two more questions..

    how do i evaluate this without a calculator?
    (sum from k=1 to k=5) of 1/k

    and what is sigma notation? it says to write 1+2+4+8+16+32 in sigma notation

    sorry i'm so lost i hate missing class!!
    Last edited by holly123; December 15th 2008 at 01:47 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member euclid2's Avatar
    Joined
    May 2008
    From
    Ottawa, Canada
    Posts
    400
    Awards
    1
    Quote Originally Posted by holly123 View Post
    sorry i have two more questions..

    how do i evaluate this without a calculator?
    (sum from k=1 to k=5) of 1/k

    and what is sigma notation? it says to write 1+2+4+8+18+32 in sigma notation

    sorry i'm so lost i hate missing class!!
    Should it be 16 rather then 18?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Nov 2008
    From
    MD
    Posts
    165
    yes sorry typo!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member euclid2's Avatar
    Joined
    May 2008
    From
    Ottawa, Canada
    Posts
    400
    Awards
    1
    Quote Originally Posted by holly123 View Post
    sorry i have two more questions..

    how do i evaluate this without a calculator?
    (sum from k=1 to k=5) of 1/k

    and what is sigma notation? it says to write 1+2+4+8+16+32 in sigma notation

    sorry i'm so lost i hate missing class!!
    Note: a sigma notation is a way to write out a long sum

    \sum_{k=0}^5 2^k is the sigma notation for that sequence



    \sum_{k=0}^5 2^k = 2^0+2^1+2^2+2^3+2^4+2^5= 1+4+8+16+32 = 63

    Does that match the book answer?
    Last edited by euclid2; December 15th 2008 at 02:17 PM.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Nov 2008
    From
    MD
    Posts
    165
    yes thank you very much that makes sense
    how would i do 1+1/4+1/9+1/16
    would it be (1)/(x^2) from 1 to 4?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Senior Member
    Joined
    Dec 2007
    From
    Melbourne
    Posts
    428
    how do i evaluate this without a calculator?
    (sum from k=1 to k=5) of 1/k
    Find a common denominator and convert all of the fractions to it, then add up the numerators. I know it seems like you should know a better way by now, but I don't think there is one.

    how would i do 1+1/4+1/9+1/16
    would it be (1)/(x^2) from 1 to 4?
    exactly. Very good.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Member
    Joined
    Nov 2008
    From
    MD
    Posts
    165
    thank you! im still confused on summations though.
    f(x)= 1/(x+1) from [0,1] and n=2
    how do i set up the summation for LRAM, RRAM, MRAM, and the trapezoidal method?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Help with summations.
    Posted in the Algebra Forum
    Replies: 1
    Last Post: January 25th 2011, 11:37 AM
  2. Summations
    Posted in the Discrete Math Forum
    Replies: 7
    Last Post: December 6th 2010, 07:22 AM
  3. summations
    Posted in the Algebra Forum
    Replies: 5
    Last Post: September 27th 2010, 04:23 AM
  4. Summations please help!!!
    Posted in the Differential Geometry Forum
    Replies: 5
    Last Post: November 15th 2009, 01:01 AM
  5. Summations
    Posted in the Calculus Forum
    Replies: 0
    Last Post: October 26th 2008, 11:37 AM

Search Tags


/mathhelpforum @mathhelpforum