math

help me with sequences problem.So if the sequence is 2,5,10,17,26
+3 +5 +7 +9 1st difference
+2 +2 +2 2nd difference
then the nth term can be worked out by writing out :
n 1 2 3 4
n squared 1 4 9 16
original sequence 2 5 10 17
nth term= n squared+1

but what about this question:
8, 10, 14, 20, 28
+2 +4 +6 +8
+2 +2 +2

n 1 2 3 4
n squared 1 4 9 16
original sequence 8 10 14 20 the number you have to add to n squared is different every time so does anybody know how too get the nth term for this sequence?

  1. 👍 0
  2. 👎 0
  3. 👁 51
  1. help me with sequences problem.So if the sequence is 2,5,10,17,26
    +3 +5 +7 +9 1st difference
    +2 +2 +2 2nd difference
    then the nth term can be worked out by writing out :
    n 1 2 3 4
    n squared 1 4 9 16
    original sequence 2 5 10 17
    nth term= n squared+1

    but what about this question:
    8, 10, 14, 20, 28
    +2 +4 +6 +8
    +2 +2 +2

    n 1 2 3 4
    n squared 1 4 9 16
    original sequence 8 10 14 20 the number you have to add to n squared is different every time so does anybody know how too get the nth term for this sequence?

    With 2nd differences being equal, the general expression is of the form an^2 + bn + c

    8, 10, 14, 20, 28
    .+2. +4. +6. +8
    ...+2. +2. +2

    a(1)^2 + b(1) + c = 8
    a(2)^2 + b(2) + c = 10
    a(3)^2 + b(3) + c = 14

    a + b + c = 8
    4a + 2b + c = 10
    9a + 3b + c = 14

    Solving, a = 1, b = -1 and c = 8.

    Thus, the nth term derives from N = n^2 - n + 8.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. I don't get this math!

    Sequences that increase at increasing rates are sometimes described as “growing exponentially”. However, this is not always a correct use of the word. For example, both quadratic (constant second difference) and exponential

    asked by Sara V. on May 3, 2017
  2. Maths

    Eric thinks of 2 sequences.One is geometric and the other arithmetic.Both sequences start with the number 3.The common ratio of the geometric sequence is the same as the common difference of the arithmetic sequence.If the 6-th

    asked by Lucas on February 3, 2013
  3. Biology

    When making comparison of sequences where some are whole genome sequences while others are partial genome sequences, or a specific glycoprotein sequence, How is it that we are able to make comparisons from these sequences if they

    asked by Cristian on April 21, 2013
  4. Biology

    Humans and Gorillas are very similar in terms of their genetic sequences; in a sample of each of their DNA sequences, only ONE difference was found. MY QUESTION: What genetic mechanism could cause this base sequence change?

    asked by Millwright on June 4, 2008
  5. Math

    These are the first 5 terms of a quadratic sequence: 1 3 7 13 21 1st difference: 2 4 6 8 2nd difference: 2 2 2 1n^2: 1 4 9 16 25 adjustment: ? ? ? ? ? Thank you very much.

    asked by Elisha on January 3, 2017
  6. Algebra 2 Honors

    Right now in my class i am learning about sequences and series and im currtently suck on this problem. "A certain sequence is defined recursively by the t1=1 , t2=2, t2n=2t2n-2, t2n+1=3t2n-1. Find the first eight terms of the

    asked by Stephanie on May 12, 2008
  7. biology

    Below the human hemoglobin sequence are the first thirty amino acid sequences of several other species’ hemoglobins. Inspect the sequences and answer the following questions: Human) h l t p e e k s a v t a l w g k v n v d e v g

    asked by Kim on April 1, 2012
  8. Math

    Find the arithmetic sequence whose 1st term is 1 and the 1st, 2nd and 6th terms form a geometric sequence

    asked by Gly on July 16, 2017
  9. mathematics

    THE 1ST, 3RD AND 9TH TERM OF A LINEAR SEQUENCE A.P ARE THE 1ST THREE TIMES OF G.P. IF THE 7TH TERM OF THE LINEAR SEQUENCE IS 14. CALCULATE (A) 20TH TERM OF THE LINEAR SEQUENCE (B) SUM OF THE 1ST, 12TH TERM OF THE G.P

    asked by AYOMIDEY on March 5, 2015
  10. Math

    I'm learning series and sequences (grade 11). Please check that my steps show I understand what I'm doing/the concept and my answer as well: 5. The consecutive terms of an arithmetic sequences are 3.6, y, 8.2. Find the value of y.

    asked by Crystal on January 8, 2013

More Similar Questions