# Math Help - Sigma Notation

1. ## Sigma Notation

How do you find how many terms this has if the lower limit is k=b and the upper limit is b+12, i know you subtract them and add 1, but i'm not sure how to do it with this

Thanks

2. Originally Posted by nuckers
How do you find how many terms this has if the lower limit is k=b and the upper limit is b+12, i know you subtract them and add 1, but i'm not sure how to do it with this

Thanks
What are we trying to sum?

3. not trying to sum anything up, just asking for the number of terms in each series

not sure how this is typed on here but i'll try and explain it

sigma sign, on the top is b+12 and on the bottom is k=b, and the equation is 3n-7

4. Originally Posted by nuckers
not trying to sum anything up, just asking for the number of terms in each series

not sure how this is typed on here but i'll try and explain it

sigma sign, on the top is b+12 and on the bottom is k=b, and the equation is 3n-7
If the counter starts at $b$ and ends with $b + 12$, how many terms are there?

5. Originally Posted by Prove It
If the counter starts at $b$ and ends with $b + 12$, how many terms are there?
12 terms?

6. Originally Posted by nuckers
12 terms?
No, 13. You've forgotten the starting term.

7. Originally Posted by Prove It
No, 13. You've forgotten the starting term.
oops, that would explain the +1, got a little confused with the K=b and the b+12
Thank you