SOLUTION: -10, -7, -4, -1, 2, 5, 8, 11, 14, 17, 20. How to turn this into Sigma notation. Please

Algebra ->  Sequences-and-series -> SOLUTION: -10, -7, -4, -1, 2, 5, 8, 11, 14, 17, 20. How to turn this into Sigma notation. Please       Log On


   

Question 1164850: -10, -7, -4, -1, 2, 5, 8, 11, 14, 17, 20. How to turn this into Sigma notation. Please
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Did you mean:

(-10)+(-7)+(-4)+(-1)+(2)+(5)+(8)+(11)+(14)+(17)+(20)

with plus signs between?

If so, find the general formula for the arithmetic sequence with

a%5B1%5D=-10andd=3

by substituting in:

a%5Bn%5D=a%5B1%5D%2B%28n-1%29d

a%5Bn%5D=-10%2B%28n-1%293

a%5Bn%5D=-10%2B3n-3

a%5Bn%5D=3n-13

Then summing that from 1 to 11, since there are 11 terms:

sum%28%283n-13%29%2Cn=1%2C11%29

Edwin