Question

Given the geometric sequence where a1 = 4 and the common ratio is 3, what is the domain for n?
All integers where n ≥ 1
All integers where > 1
All integers where n ≥ 4
All real numbers

Answer 1

I'm not able to be of assistance, I'm sorry. They can try and help, if not, tag some more people. :) @ParthKohli @Hero

Answer 2

@iGreen

Answer 3

start by writing out the first few terms of the sequence.

4, 12, 36, ...
do you see any restrictions on the lower end?

Answer 4

what do u mean restrictions?

Answer 5

if the first term of the sequence is 4, it can never go lower than 4.

Answer 6

okay

Answer 7

it can only increase from there because the common ratio is a positive integer

Answer 8

so the answer is C?

Answer 9

yeah

Answer 10

thank you so muchhh can u help me with one more question

Answer 11

yeah, sure

Answer 12

The population of a local species of dragonfly can be found using an infinite geometric series where a1 = 48 and the common ratio is one fourth. Write the sum in sigma notation and calculate the sum that will be the upper limit of this population.

Answer 13

gimme a second cleaning somethging

Answer 14

mmkay

Answer 15

can you write out the sigma?

Answer 16

i cant on my keyboard

Answer 17

You can use the draw button here

Answer 18

is this correct?

Answer 19

I don't think so, gimme another minute sorry lol

Answer 20

its gucci

Answer 21

only frick with hoes that rock dolce and gabanna

Answer 22

gabbana*

Answer 23

anyhow, again start by writing out the first few terms
\(48,12,3,\dfrac{3}{4},...\)

Answer 24

given that it's a geometric seq, it's of the form, \(a,ar,ar^2,...,ar^{(n-1)}\)

Answer 25

This looks hard asf

Answer 26

and so, follow the formula \[\sum_{?}^{?}ar^k\]
where a is our first term and r is the common ratio

Answer 27

so \[\sum_{k=0}^{\inf}48*\dfrac{1}{4}^k\]

Answer 28

google the sum formula. i think its on the first page here http://www.purplemath.com/modules/series5.htm

Answer 29

im sorry im really bad at math and im not picking up what ur putting down

Answer 30

The population of a local species of dragonfly can be found using an infinite geometric series where a1 = 48 and the common ratio is one fourth. Write the sum in sigma notation and calculate the sum that will be the upper limit of this population.

the way you write sigma notation for geometric series, is first term times the common ratio raised to the sigmas power

think about why this works. if we start counting at 0, anything raised to the 0 power is 1, so we have \(48*\frac{1}{4}^0=48*1=48 \) for our first term

Answer 31

okay i understand that now.

Answer 32

can you plug in the information we have into this?

Answer 33

wait, whoops

Answer 34

it's just a/(1-r)

Answer 35

yall be on this for good decade

Answer 36

it feels like 2 or 3 decades. my kids have moved out and my wife left me
damn