Question

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

Answer 1

I know...nothing. So lost here...

Answer 2

\[\sum_{n=2}^{n=5}(2n)\]

Answer 3

Here : 4 + 6 + 8 + 10

So, it can be written as (they are multiples of 2) :

\[2 \times 2, 3 \times 2, 4 \times 2, 5 \times 2\]

If I let 2, 3, 4,5 as n, then:

\[2 \times n, 2 \times n, 2 \times n, 2 \times n = 2n, \; 2n, \; 2n, \; 2n\]

So here, \(n\) varies form 2 to 5:

And Series is simply 2n:

\[\huge \color{red}{\sum_{n = 2}^{n=5}(2n)}\]