Question

Find a1 for the given geometric series
Sn= 89205 R=4 N=11

ANSWERS:
A: 0.11
B: 0.06
C. 8089.55
D: 60.93

Answer 1

Where is the equation ?

Answer 2

Do you know the equation of the the sum of a geometric series?

Answer 3

no the question only says what i wrote above ^ i'm really confused

Answer 4

Ok, well the equation for a geometri series (a series is a sum of numbers ina sequece and a sequence is just a list of numbers) is
\[\Huge S _{n}=a _{1}(\frac{1-r^n}{1-r})\]

Answer 5

Sn=the sum of the numbers
a1=the first term of the series, and what we're trying to find
r=the common ratio, which is the number that you multiply the previus number to
n=the number of terms

Well we have Sn, r, and n, so all we have to have to is substitute and find a1 which in this is our x

Answer 6

idk

Answer 7

here r=4 >1

so Sn = a1. (r^n-1) /(r-1)

or
a1=((r-1)*Sn)/( (r^n-1)

Answer 8

True^ @matricked

Answer 9

here r=4 ,n=11

Answer 10

because r =4> 1 (diverges) that classifies S_n = a1? How so...just wondering.

Answer 11

check whether ans u have posted are of the same question

Answer 12

I was just referring to your post

"matricked
here r=4 >1

so Sn = a1. (r^n-1) /(r-1)

or
a1=((r-1)*Sn)/( (r^n-1)"

Answer 13

the question and answers i posted are from the same question. those are the selected answers

Answer 14

Well you've been gien the equation \[\Huge a_1=\frac{ (r-1)S_n }{ r^n-1 }\]

Answer 15

And you have r,n,and Sn

Answer 16

\[a _{1}= (3)(89205)\div 4^{10}\]

Answer 17

a bit change
a1= ((3)(89205))÷(4^11 -1) = 0.0638 appx =0.06

Answer 18

thank you i get it now

Answer 19

yw