Confused completely by sigma notation!?

Question

I just can't do this; can anone help please? Let E=sigma Use properties of summation to evaluate:
5
E(1/2i^2-1/4i-1/8)
i=1

Many thanks in advance!

Answer 1

Alright. i=1-5,because the number on the bottom is the first number you will put in the expresion, and the number on top is the last number.and you put all the number inbetween in the expression too. So i will equal 1, 2, 3, 4, 5. Plug each one into the expression next to E. Now you have 5 answers. Sigma means something like "add" so you add all 5 answers together, and that is the final answer.

Answer 2

5
E(1/2i^2-1/4i-1/8)
i=1
put i=1,2,3,4,5
turn by turn and add
=(1/2-1/4-1/8)+
(1/8-1/8-1/8)+
(1/18-1/12-1/8)+
(1/32-1/16-1/8)+
(1/50-1/20-1/8)