Monday

March 30, 2015

March 30, 2015

Posted by **Tk** on Monday, March 21, 2011 at 6:02am.

- arithmetic -
**Reiny**, Monday, March 21, 2011 at 8:58amthe general term of a quadratic sequence is

term(n) = an^2 + bn + c, where a, b, and c are constants

It can be shown using differences that a is (1/2) of the second difference.

Thus a = 1

so term(1) = 8

8 = 1(1^2) + b(1) + c ---> b+c = 7

term(4) = 32

32 = 1(2^2) + b(2) + c ---> 2b + c = 28

subtract them: b = 21

then c = 7-21 = -14

term(n) = n^2 + 21n - 14

- correction - arithmetic -
**Reiny**, Monday, March 21, 2011 at 9:07amI used the 32 as if it were the 2nd terms, should have been the 4th

Here is the correct version

Thus a = 1

so term(1) = 8

8 = 1(1^2) + b(1) + c ---> b+c = 7

term(4) = 32

32 = 1(4^2) + b(4) + c ---> 4b + c = 16

subtract them:

3b = 9

b = 3

then c = 7-3 = 4

term(n) = n^2 + 3n + 4

check:

t(1) = 1+3+4 = 8

t(4) = 16 + 12 + 4 = 32

**Answer this Question**

**Related Questions**

Algebra - True or False 1. – 5, – 5, – 5, – 5, – 5, … is an arithmetic sequence...

Math - A sequence is formed by adding together the corresponding terms of a ...

Arithmetic Sequence - Given the third term of an arithmetic sequence less than ...

Maths - 1..The first 2 terms of a geometric progression are the same as the ...

Mathematics : Arithmetic Sequence - The 5th term and the 8th term of an ...

math - The 3rd term in an arithmetic sequence is 12, the 7th term is 24, a) How...

math - in an arithmetic sequence the common difference is equal to 2.the first ...

maths - The difference between the second and fourth terms of an arithmetic ...

math - find the rule for the Nth term of the arithmetic sequence. 11/2, 25/6, 17...

Algebra - Determine whether each sequence is arithmetic or geometric. Find the ...