Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

teachme1234

find the sum ∑_(n=1)^100▒2n

  • one year ago
  • one year ago

  • This Question is Closed
  1. satellite73
    Best Response
    You've already chosen the best response.
    Medals 0

    hmmm

    • one year ago
  2. Australopithecus
    Best Response
    You've already chosen the best response.
    Medals 0

    is this summation censored?

    • one year ago
  3. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    no

    • one year ago
  4. satellite73
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\sum_{n=1}^{100}2n\]?

    • one year ago
  5. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

    • one year ago
  6. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\sum_1^{100} 2n=2 \cdot \sum_1^{100} n=2\cdot {n(n+1) \over 2}\]

    • one year ago
  7. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 1

    Where \(n=100\)

    • one year ago
  8. satellite73
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\sum_{k=1}^nk=\frac{n(n+1)}{2}\] so ... what king george said

    • one year ago
  9. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    still not getting it

    • one year ago
  10. Australopithecus
    Best Response
    You've already chosen the best response.
    Medals 0

    you can add them all up like 2(1) + 2(2) + 2(3)... or you can just use a formula to solve for it which is much quicker

    • one year ago
  11. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    we are counting from 1 to 100 what is the nth term.

    • one year ago
  12. Australopithecus
    Best Response
    You've already chosen the best response.
    Medals 0

    100 terms sorry

    • one year ago
  13. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    2xn(n+1)/2 so i use this fromula to solve it.

    • one year ago
  14. colorful
    Best Response
    You've already chosen the best response.
    Medals 0

    in general \[\sum_{i=1}^{n} i={n(n+1)\over2}\]

    • one year ago
  15. Australopithecus
    Best Response
    You've already chosen the best response.
    Medals 0

    (2)100(100+1)/2 = 10100 proof https://www.wolframalpha.com/input/?i=summation+of+1+to+100+of+2n

    • one year ago
  16. Australopithecus
    Best Response
    You've already chosen the best response.
    Medals 0

    if you want to understand the formula I recommend just looking up sum of arithmetic formula on wiki

    • one year ago
  17. Australopithecus
    Best Response
    You've already chosen the best response.
    Medals 0

    or you can just accept it

    • one year ago
  18. colorful
    Best Response
    You've already chosen the best response.
    Medals 0

    the rules of summations are such that we can take constants out of the summation sign\[\sum_{i=1}^{n} Ci=C\sum_{i=1}^{n} i=C{n(n+1)\over2}\]where C is any constant that is how we got our formula

    • one year ago
  19. colorful
    Best Response
    You've already chosen the best response.
    Medals 0

    The proof is quite easy if you know mathematical induction if not, it's better to just accept it, or look up the formula for any arithmetic series the wiki way, as suggested by @Australopithecus

    • one year ago
  20. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    okay so c=2 n=100

    • one year ago
  21. colorful
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

    • one year ago
  22. teachme1234
    Best Response
    You've already chosen the best response.
    Medals 0

    okay got it thanks

    • one year ago
  23. colorful
    Best Response
    You've already chosen the best response.
    Medals 0

    welcome

    • one year ago
    • Attachments:

See more questions >>>

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.