State whether the sequence is an arithmetic sequence. If it is find the common difference, and graph the sequence. And find the equation of the sequence.

1. -8, -4, 0, 4 ..........

2. 2, 4, 8, 16 ..........

Nerd123 Dec 13, 2018

#1**+2 **

The first is definitely arithmetic

The common difference between terms is 4

The sequence can be expressed as

a_{n+1} = a_{n} + 4 where a_{1} = - 8

I'm not used to finding an graph for these, but here's a possibilty

y = -8 + 4(x - !)

y = -8 + 4x - 4

y = 4x - 12

[ Where x is an integer...and x = 1 gives the 1st term, -8, x = 2 gives the 2nd term, -4.....etc .]

Here's the graph : https://www.desmos.com/calculator/pewqtw4vmg

The second is not arithmetic....the difference between 2 and 4 is 2......the difference between 8 and 4 is 4.......thus.....the common difference between terms is not constant as required in an arithmetic series

CPhill Dec 13, 2018