Question

Sigma Notation ;/ ?

Answer 1

I can't help in math :(

Answer 2

@FibonacciChick666 @ganeshie8

Answer 3

@King.Void. ok no problem... :) thanks anyways

Answer 4

-7 for-2times2-3

Answer 5

^_^ HEY GABY

Answer 6

@Warriorz13 heyyyy ^-^

Answer 7

Does you remember me?

Answer 8

@Warriorz13 ofc cx

Answer 9

YAY XD

Answer 10

are u not needing help on this

Answer 11

I've missed you. You never reply to my PM

Answer 12

@james1107 yes.. i dont understand what u said..

Answer 13

@Warriorz13 sorry i get so many pms i stopped checking .-.

Answer 14

-2 times positive 2 -3 right
equals 7

Answer 15

Oh....

Answer 16

still there

Answer 17

yes @james1107

Answer 18

@james1107 and then what lol

Answer 19

\[\large \sum_{n=2}^{10}-2n-3\]

the summation is nothing but the sum of all values of \(\color{orangered}{-2n-3}\) on putting n=2 and then 3 and then 4... till 10

the terms that you'll be getting are-
put n=2-> \(\color{blueviolet}{-2n-3}\) =-7
put n=3->\(\color{blueviolet}{-2n-3}\) =-9
put n=4-> \(\color{blueviolet}{-2n-3}\) =-11
.
.
put n=10->\(\color{blueviolet}{-2n-3}\) =-23

note that total number of terms= 9

so all the terms form and arithmetic series \(\color{hotpink}{-7,~-9,~-11,~-13..-23}\)
and we need to find sum of all these numbers
so apply the formula to find the sum of Arithmetic series-

\(\large Sum= \frac{no.~of~terms}{2}\left[2(1^{st} term) +(no.~of~terms -1)(common~difference)\right]\)

Answer 20

i cant see most of it ;/ @imqwerty i cant see after (common diff

Answer 21

\(Sum= \frac{no.~of~terms}{2}\left[2(1^{st} term) +(no.~of~terms -1)(common~difference)\right]\)

Answer 22

\[Sum = \frac{ 9 }{ 2 }[2(-7) + (9 - 1)(common difference) \]

Answer 23

whats common difference ?

Answer 24

common difference is the difference between any two consecutive terms of the series

like-> \((n+1)^{th} \) term - \(n^{th}\) term

Answer 25

i got -135 ?

Answer 26

yeah thats correct