Question

Need help with arithmetic series (screen shot)

Answer 1

I get what it means, I just don't know how to solve one that big

Answer 2

Let i = 1 to 1000 for each term

find the sum from i = 1000, in 2i

n(1) = 2(1)
n(2) = 2(2)

the sum of 2i from 1 to 1000 = n(1)+n(2)+n(3)+...n(1000)

There is a short cut to doing it, but that is what it means

Answer 3

I get that part

Answer 4

\[\sum_{k=1}^nk=\frac{n(n+1)}{2}\] a very useful formula

Answer 5

you have
\[\sum_{i=1}^{1000}2i=2\sum_{i=1}^{1000}i=2\times \frac{1000(1001)}{2}=1000(1001)\]