A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

A sequence is defined by the formula f(n + 1) = f(n) – 3. If f(4) = 22, what is f(1)?

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

    the part `f(n+1)=f(n)-3` tells us that the common defference is d=3. Then, we are given that f(4)=22. So this is what we can do: We know a formula for any nth term in arithmetic sequence (this sequence is also arithmetic): \(a_n=a_1+{\rm d}(n-1)\) Now, for 4th term, it would be: \(a_4=a_1+{\rm d}(4-1)\) \(a_4=a_1+3{\rm d}\) Then you know that\(a_4=22\) and d=-3 So, \(22=a_1+3{\rm (-3)}\)

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

    So solve for \(a_1\). (apologize for going from notation of f(n) to \(a_n\), and hope that is ok:) )

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

    It's fine and is the answer 31? I'm going to add this is my notes!

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

    \(22=a_1+3(-3)\) \(22=a_1-9\) \(31=a_1\) yes, 31 is correct.

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

    I apologize, I had to depart (buying stuff at home depot for fuuture further bath constructions)

  6. 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.