Question

Graph the 6 terms of a finite series where a1=-3 and r=1.5

Answer 1

@iamrobin can you help me?

((i love 2009 teen titans so much~~))

Answer 2

@satellite73

Answer 3

@gabgurl

Answer 4

-3(1.50)-3=7.50
-7.50(1.50)-3=-14.25
-14.25(1.50)-3=-24.38
-24.38(1.50)-3=-39.56
-39.56(1.50)-3=-62.34

Answer 5

@nincompoop

Answer 6

how are you determining those?

Answer 7

a = first sequence
r = factor between the terms

Answer 8

i used a formula it is...

Answer 9

sm=ai-air^m/1-r

Answer 10

can you type that clearer?
\(\huge s_m = \frac{a_i - ar^m}{1-r} \)

Answer 11

first, you need to identify what kind of sequence it is

Answer 12

instead of m its n

Answer 13

its a geometric

Answer 14

okay, now that you know it is geometric, use this \(\large x_n = ar^{n-1} \) where a is your first term and r is the common ratio.
then it follows:

\(\huge x_\color{red}{6} = -3(1.5)^{\color{red}{6-1}}\)

Answer 15

make sure you apply the order of operations, PEMDAS

Answer 16

i know how to solve it, but its saying what graph is it

Answer 17

let me see the whole question and choices

Answer 18

I don't know how you determined the 7.50 in your first line of equation

Answer 19

it says graph the six terms, I gave you how to do look for the value of the 6th term
now do it for 5th, 4th, 3rd down to the 1st term
finally, plot it

Answer 20

the graph that I am looking at is perhaps one of the choices or that was something you did?

Answer 21

im posting the choices now

Answer 22

okay, before you do that. Will you look for the rest of the terms?
then list here the six terms in the geometric sequence

Answer 23

but the question is only asking for the first 6 term

Answer 24

You mentioned that you knew the "formula," but I didn't really see you apply it to obtain the first 6 terms of the geometric sequence based on \(a \) and \( r\) provided.

Answer 25

the first term is already given a1=3
-3(1.50)-3=7.50
-7.50(1.50)-3=-14.25
-14.25(1.50)-3=-24.38
-24.38(1.50)-3=-39.56

Answer 26

wrong formula

Answer 27

its the same formula isnt it?

Answer 28

no

Answer 29

\(\large x_n = a(r)^{n-1}\)
where:
\(n \) :is the \(n^{th}\) term you are looking for
\(a \) :1st sequence
\(r\) :common ratio

your common ratio has to be fixed and always remain the same, so you are correct; and your first term is always fixed because there is only ONE first sequence; finally, the n changes depending on which sequence you are looking for

Answer 30

i dont get you, you say i am correct but at the same time the formula is incorrect? :/

Answer 31

read everything

Answer 32

in the question, the have already given me the first term, its what the graph starts with. can i post the graphs and can you give me my opinion and ill tell you which one a i chose?

Answer 33

also, how would you graph it in geogebra?

Answer 34

you are correct that the common ratio remained the same in your list of values
you are incorrect about maintaining the same value of the \(n^{th} \)term. it changes as you look for the specific term
example: if you want to look for the 5th term, you use n=5
so it becomes \(\large x_5 = -3 \times (1.5)^{5-1} \)

Answer 35

how do i graph xn=a1r^n-1 in geogebra? because i tried but it doesnt recognize it

Answer 36

http://www.wolframalpha.com/input/?i=graph+%28f%28x%29%3D-3*%281.5%29%5E%28x-1%29%29

Answer 37

think about this: you gave this list
-3(1.50)-3=7.50
-7.50(1.50)-3=-14.25
-14.25(1.50)-3=-24.38
-24.38(1.50)-3=-39.56

Notice how your first sequence is not -3. IT has to be -3 and I will demonstrate why you are you using the formula correctly.

let us solve for the 1st term, that is n = 1
\(\large x_1 = -3 \times (1.5)^{1-1} \rightarrow x_1 = -3 (1.5)^{0} \rightarrow x_1 = -3 \times 1 = -3 \)

any number, except zero, whenever it is raised to zero is equal to 1

Answer 38

I meant to say that you are using the formula INCORRECTLY

Answer 39

can you please just give me your opinion on what the answer is? im gonna lose wifi. when i used your formula, none of the values i got show up on any of the options i have

Answer 40

because you are using the formula INCORRECTLY!

Answer 41

1st term: n = 1
2nd term: n = 2
3rd term: n = 3
4th term: n = 4
5th term: n = 5
6th term: n = 6

\(\large x_n = -3(1.5)^{n-1} \)
use the values of n accordingly

Answer 42

first term \(\large x_1 = -3(1.5)^{1-1}\)
second term \(\large x_2 = -3(1.5)^{2-1}\)
third term \(\large x_3 = -3(1.5)^{3-1}\)
fourth term \(\large x_4 = -3(1.5)^{4-1}\)
fifth term \(\large x_5 = -3(1.5)^{5-1}\)
sixth term \(\large x_6 = -3(1.5)^{6-1}\)

Answer 43

do you get it yet?