Question

SOMEONE HELP
(Picture Below)

Answer 1

There is no n in the expression... Sure that it is the question is right?

Answer 2

Yes this is the right question

Answer 3

i think further info is needed

Answer 4

is this the whole question ?

Answer 5

What the picture says is my question, Thats why i need help. Yes it's the whole question.

Answer 6

hmm its a little out of my range. so i might get it wrong. ill leave it up to @SmartWish

Answer 7

good luck

Answer 8

@phi can you help me please

Answer 9

The question is incomplete, it should be an n in the expression as far as i know

Answer 10

But there isnt . Whats posted is the question. I dont understand.

Answer 11

I think the x is a typo, and they mean n

do you have the formula for the sum of a geometric series ?

Answer 12

No . i dont understand this problem at all thats why i need your help. There probably is a typo, but i have no idea. Whats on that picture above is my question.

Answer 13

See
http://www.mathsisfun.com/algebra/sequences-sums-geometric.html

scroll down to summing a geometric series

Answer 14

I did and there probably is a typo, but does that mean i cant get help.

Answer 15

@phi

Answer 16

the formula is
\[\sum_{x=0}^{N-1}ar^x = a \left( \frac{ 1-r^N }{ 1-r } \right)\]

Answer 17

Okay thank you. keep explaining please.

Answer 18

match the formula to your problem

what is "a" in your problem

Answer 19

alrighty thank you

Answer 20

in sigma there is N and in equation there is x?!!

Answer 21

can you help me with this problem to @phi

Answer 22

can you identify what is "a" ? and what is r ?

Answer 23

for which one ?

Answer 24

your first problem (the one with the typo)

Answer 25

ok hold on

Answer 26

I still dont get it

Answer 27

your second problem is : it converges it has a sum (C)

Answer 28

okay @Roh so what do i do to get my answer?

Answer 29

look the denominator is decreasing so it converges to 0 you can just prove it and cannot get the exact number

Answer 30

okay and whats next

Answer 31

\[\sum_{n=1}^{\infty} \frac{ 1 }{ 5n }\] this is how ur problem can be expressed

Answer 32

wait are we talkinmg about the same problem.

Answer 33

oh my god, we are discussing about the second problem of yours and i expressed your second problem in a sigma form ,so you can prove that the denominator is increasing so it converges to 0

Answer 34

@SmokeysTheName

Answer 35

@Roh it converges; it has a sum
is that the right answer?

Answer 36

@SmokeysTheName according to me yes it is the right answer

Answer 37

okk