Forum — Daily Challenge

    • Login
    • Search
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups

    Should this mini-question have been clearer?

    Pattern in a Pattern
    3
    5
    23
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • P
      professionalbronco M0★ M1★ M2★ M3 M5★ last edited by

      When they said "second common difference", I thought that was a little bit confusing. Should this maybe have been changed to "difference of any two consecutive terms" or something like that?

      The Daily Challenge with Po-Shen Loh is the best!
      aops user = captainnobody

      1 Reply Last reply Reply Quote 0
      • Legendaryboy991
        Legendaryboy991 M0 last edited by

        can you show a snapshot?

        P 1 Reply Last reply Reply Quote 0
        • P
          professionalbronco M0★ M1★ M2★ M3 M5★ @Legendaryboy991 last edited by

          @legendaryboy991 Okay.DailyChallengeCommonDifferenceProblem.JPG

          The Daily Challenge with Po-Shen Loh is the best!
          aops user = captainnobody

          quacker88 1 Reply Last reply Reply Quote 0
          • quacker88
            quacker88 MOD @professionalbronco last edited by quacker88

            Hey @professionalbronco , good question! I understand where you're confused-- "common" is a bit confusing since the differences aren't the same the first time. But, there is a difference between the "difference of two consecutive terms" and the "second difference".

            For example, the five few terms of sequence with formula \(2n^2+n\) are \(3,10,21,36,55\)

            The difference between two consecutive terms is \(7,11,15,19\). You can think of this as the "first difference".

            The differences between the terms of our new sequence \(7,11,15,19\) is \(4,4,4,4\). We just took the common difference OF the common differences, so this is the "second" difference!

            Doing this process again, the third difference of the terms will be \(0,0,0\). Hope this makes sense!

            P 1 Reply Last reply Reply Quote 1
            • P
              professionalbronco M0★ M1★ M2★ M3 M5★ @quacker88 last edited by

              @quacker88 ohh, I see. Thanks!

              The Daily Challenge with Po-Shen Loh is the best!
              aops user = captainnobody

              1 Reply Last reply Reply Quote 0

              • 1 / 1
              • First post
                Last post
              Daily Challenge | Terms | COPPA