Question

Write 4 + 6 + 8 + 10 in sigma notation.

Answer 1

Is it \[\sum_{n=2}^{4}2n\]

Answer 2

It would be correct only if we had stopped at N = 4

Answer 3

Plug in the N into your function in front of the sigma and you will find you are missing something

Answer 4

so 5 over the sigma?

Answer 5

Correct! since 2n when N = 5 is 10 and we have the given and from 2-4 it is only three values if we include N=2 and we have 4 values so we were only missing 1

Answer 6

Awesome! :) I have another. Write 1/5 + 1/6 + 1/7 in sigma notation. Is it \[\sum_{x=5}^{7}1\]

Answer 7

Oops Should be 1/x