Question

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Answer 1

You have yo build a sum, that means you have to find a pattern, for example in (1) it could be
sum from 2 to 5 of 2n \[\sum_{2}^{5} 2n\]
in (2) you can do it with \[\sum_{1}^{3} (1/(n+4))\]

Answer 2

im confused.. how would i put 468 and 10 in that?? @Umangiasd

Answer 3

it's 4 plus 6 plus 8 plus 10
if n=2 2n=4
if n=3 2n=6
if n=4 2n=8
if n=5 2n=10
Clearer?

Answer 4

a little..now sigma not. for that 2 on top...10 on the bottom? @Umangiasd

Answer 5

@Umangiasd

Answer 6

sigma is the symbol of a summatory, it means that by replacing (in order, first) the incognita , "n" in our examples, we will be adding, our evaluated "equation" in the order given by n, where at the bottom of the sigma is the NATURAL number to start and at top the number to end this. Think of sigma as the operator that tells you to replace and add, continously with natural numbers the formula on its side, starting with the number at bottom and ending with the number at top.

Answer 7

ok..

Answer 8

Im trying to apply that to #1 AND 2

Answer 9

like..what goes on top of the E and what goes o the bottom??

Answer 10

natural numbers, you have your sigma, at bottom you have, for example in (1) a number 2, that means that you start evaluating in for n=2

Answer 11

ok..

Answer 12

so n=2 at the bottom?

Answer 13

for 1, as i wrote it, it varies according to your summatory

Answer 14

so sigma notation isnt the E.. its spelled out ??

Answer 15

the sigma notation represents a summatory, the "E" as you call it, is sigma xD

Answer 16

It's a way to represent a discrete function

Answer 17

OK..can you show me on #1 please

Answer 18

@Umangiasd

Answer 19

the discrete function that i wrote was F(n)=2n, so (assuming you know what a discrete function is) when you evaluate just the function you obtain 1 result, for example, if n=5 F(5)=10. Now, the summatory does this; \[\sum_{2}^{5} F(n)\]= F(2)+F(3)+F(4)+F(5) = 4 + 6 + 8 +10
Then, for every case when you have to "discover" a summatory, just fin a pattern, and make it start at some point and stop at other. The start point goes at the bottom of the sigma (like the "2" on the example) and the stop point at "5"