A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

egbeach

  • one year ago

Find an equation for the nth term of the arithmetic sequence. -3, -5, -7, -9, ...

  • This Question is Closed
  1. freckles
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    arithemtic sequences are well known for their common difference

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

    so first step: find common difference

  3. Haseeb96
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @freckles are you help her or should i help her?

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

    it doesn't matter

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

    go for it

  6. Haseeb96
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay you carry on

  7. Haseeb96
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i am busy some other areas

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

    ok -3, -5, -7, -9, ... common difference can be found be taking a term and subtracting its previous term

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

    -2

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

    what is -5-(-3)?

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

    yes that is right

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

    \[a_n=a+d(n-1) \\ \text{ so } d=-2 \\ a_n=a-2(n-1)\] a is suppose to represent the first term

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

    what is your first term

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

    -3

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

    so replacing a with -3 don't replace a_n with anything a_n thing we are finding \[a_n=-3-2(n-1)\]

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

    thank you!

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

    and as you can see we get all the terms when pluggin n=1,2,3,... \[a_1=-3-2(1-1) \\ a_1=-3-2(0) \\ a_1=-3 \\ a_2=-3-2(2-1) \\ a_2=-3-2(1) \\ a_2=-3-2 \\ a_2=-5 \] and so on ,,,

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

    we will find find that a_n=-3-2(n-1) that a_3=-7 and a_4=-9

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

    and so on... `

  20. 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.