Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is the solution to ΣΣ(sinx)(cosx)?

  1. Dec 4, 2007 #1
    what is the solution to this ?
  2. jcsd
  3. Dec 4, 2007 #2
    Your question isn't clear. What variables are you summing over? And where do those appear in the summand?
  4. Dec 6, 2007 #3
    Are one of the trig functions supposed to be a function of y?
  5. Dec 6, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor

    Since there was no y mentioned in the entire post, apparently not! But Xevarion's point is more than that. Typically "x" (or "y") in a function represents a continuous variable- but the sums must be over discrete indicies.

    Perhaps it was
    [tex]\sum_{n= 0}^\infty \sum_{m= 0}^\infty sin(n)cos(m)[/tex]
    that was intended. But the only way we will know for sure is if abhaaiitg tells us!
  6. Dec 7, 2007 #5
    yeah it was as u think
  7. Dec 7, 2007 #6
    That sum doesn't converge. There are arbitrarily large $m, n$ with $|\sin(n)\sin(m)|$ close to 1.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?