Question

Write the sum using summation notation, assuming the suggested pattern continues. -1 + 2 + 5 + 8 + ... + 44

Answer 1

\(\Large\color{blue}{ \bf -1 + 2 + 5 + 8 + ... + 44 }\)

You can notice that its going +3 every time.
it looks like an infinite one here, and the formula that fits would be (I think)

\[\Large\color{blue}{ \bf \sum_{n=1}^{∞}~~-1+3(n-1) }\]

Answer 2

if 44 is the last point and no numbers after it, then ...

\[\Large\color{blue}{ \bf \sum_{n=1}^{12}~~-1+3(n-1) }\]

Answer 3

is it possible for n to = 0?

Answer 4

I want to ask you a couple question before I answer, okay?

Answer 5

Do you know\[\Large\color{blue}{ \bf a_{n} }~~~and~~~\Large\color{blue}{ \bf a_{n-1}}\] mean ?

Answer 6

because this is what I can pick I'm so lost

Answer 7

In this notation, on the bottom n=1, is saying that you will plug 1 (for n) into -1+3(n-1) to get the first term.
and that you will plug 2 (for n) into -1+3(n-1) to get the second term.

and that you will plug 3 (for n) into -1+3(n-1) to get the third term.

Answer 8

and with what you've already said, I think it would be the last choice?

Answer 9

Yes! It's the last one! Good job!

Answer 10

thank you so much for the help

Answer 11

No problem!