Sum of a Series?

Question

I need help on sum of a series. If anyone doesn't know what it means, it is that weird looking E. There is two numbers in the top of the E and the right of the E. There is one "n=#" sign in the bottom of the E. Can someone like give me a walkthrough on this because I am freshman in high school and I never learned this yet. I had to learn it last year, but they wouldn't let me. Can you tell me how to do it. Give me like samples of sum of a series and tell me how to solve the answer step by step. I need to know please.

I think I am talking about the sigma. I need some examples that a 9th grader could understand

Answer 1

∑ (sigma) is nothing but a notation or symbol. It's generally used for a handy representation for summation of a series in mathematics.

Look at these simple examples.
say S = 1 + 2 + 3 + ..... + 10

instead of writing like this, u can write S as equal to,
i = 10
∑ i
i = 1

i = n
∑ i = 1 + 2 + 3 + .... + n = n(n+1)/2
i = 1

i = n
∑ -1 = (-1) + (-1) + (-1) + ..... n-times = (-n)
i = 1

n = 6
∑ n³ = 3³ + 4³ + 5³ + 6³
n = 3

j = 3
∑ (2j - 1) = (2 x 0 - 1) + (2 x 1 - 1) + (2 x 2 - 1) + (2 x 3 - 1)
j = 0

j = n
∑ (2j - 1) is same as,
j = 1

j = n j = n
∑ 2j - ∑1 is equal to,
j = 1 j = 1

j = n j = n
2∑ j - ∑1 = n(n+1) - n = n²
j = 1 j = 1

Study more about these kinds of problem and u will come to know more about sigma notation.Practice more and more different types of questions.
Best of luck.

Answer 2

The weird looking E is the greek letter sigma. The number at the bottom is where you start the sequence, the number at the top is where you end it.

For example, if you have sigma from n=1 to 10, and the thing you're summing is "n", that would be 1+2+3+4+5+6+7+8+9+10.

If you have sigma from n=2 to 5, and the thing you're summing is n^2, that would be 4+9+16+25.

Hopefully that clears things up!

Answer 3

Sigma is the Greek alphabet corresponding to S in English.
S is the first letter in SUM. Hence the symbol Sigma is used to denote sum.
For further dedails, go through the answer given by Swathi,M.

Answer 4

Hi
dat notation is basically called summation.
it is all about summing up numbers from a given set of its function within a defined range
for eg.,summation of all squares from 1 to 5 is 57....
hope u got it,have a nice day...

Answer 5

What you need is a well written text. Go to a well stocked public library or university library, and weed through texts on college algebra and finite math to find ones that suit your level.

High School math texts leave things out in order for the "teacher to have something left to teach", so usually a person cannot teach themselves the topic on their own with a H.S. text.

Answer 6

that weird "e" called sigma - (Σ). the # is the starting number and and the number on top is the final point in the series.

calculate and add....

Answer 7

are u talkin abt "sigma"?