Wednesday

April 16, 2014

April 16, 2014

Posted by **PLEASE HELP** on Wednesday, September 21, 2011 at 8:34pm.

- Algebra -
**tchrwill**, Thursday, September 22, 2011 at 5:04pmFirst glance flashes "finite difference series" but there is insufficient data to confirm same.

Assuming it is, the pattern would look like the following.

n.....1.....2.....3.....4.....5...

......8....15....29....50....78...

Diff....7.....14....21....28...

Diff.......7......7.....7....

With the second differences being constant, the nth terms are defined by a second order equation of the form a(n)^2 + b(n) + c = N

Using the given (assumed data)

a(1^2)+b(1^1)+c=8 or......a+b+c = 8

a(2^2)+b(2^1)+c=15.......4a+2b+c = 15

a(3^2)+b(3^1)+c(n)=29....9a+3b+c = 29

Subtracting each successive pair yields

3a + b = 7 and

5a + b = 14

Then, 2a = 7 making a = 3.5, b = -3.5 and c = 8

Therefore, any number in the sequence is defined by N = 3.5n^2 - 3.5n + 8

**Related Questions**

algebra - a student write that an=3n+1 is a explicit formula for the sequence 1,...

algebra - Could someone check my work; 1. Generate the first five terms in the ...

Algebra 2 - The simple formula for the nth term of an arithmetic sequence is an...

Algebra - The simple formula for the nth term of an arithmetic sequence is an = ...

math - what's the explicit formula for 8,15,27

Algebra - A = - 113 and A = -213 20 40 this is an arithmetic sequence and i have...

TRIG - what is the explicit formula for the sequence 3,7,11,15

Algebra 2 - What are the first 6 terms of the sequence with the explicit formula...

algebra 2 - write an explicit formula for the sequence of 1/2, 3/7, 1/3, 5/19, 3...

another question algebra - write an explicit formula for the sequence 7,2,-3,-8...