Question

Write the sun using summation notation, assuming the suggested pattern continues. -9-4 1 6 ... 66

Answer 1

Hello there! Welcome to QuestionCove!

What pattern do you notice?

you're going from -9 to -4

and then from -4 to 1

and then from 1 to 6

do you see what number we're constantly adding the previous number by?

Answer 2

so summation notation looks something like this
\[\Large\sum_{n=a}^{b} \text{something}\]

that something is going to be the pattern and we write it using `n`

and then n = a is the lower limit and we keep finding the sum until we get to n = b

when we plug in n = a into the pattern, we should get -9 and usually a is just kept as 0 so that way when we plug in n = 1, then we get the second term in the pattern which is -4

and when we plug in b into the pattern, we should get 66