Question

http://prntscr.com/d5q4ka

Answer 1

@sooobored

Answer 2

uhhh, is the formula given as
\[h=A B^n\] or \[h= B A^n\]
???

Answer 3

@MathSucks321 are you on Jiskha that name is so for familiar and the fact your doing inequalities it looks like.

Answer 4

or is there some information missing from this problem?

Answer 5

I do go on that site to look for things, but I don't think I am a member

Answer 6

http://prntscr.com/d5q4ka
Not sure

Answer 7

oh ok, missing information

lets look at the equation when n=1

Answer 8

when n=1, then h(1)=A

when we look at the other equation h(n)= 63*(-1/3)^n
what is
h(1)= ?

Answer 9

Umm let me think

Answer 10

-21?

Answer 11

yes
so if h(1)=-21 and h(1) = A

then A=?

Answer 12

-21?

Answer 13

yup

Answer 14

ok, now lets look at values where n>1

Answer 15

so pick an n value greater than 1

Answer 16

you have it written as 5 is less than 1

but 5 is greater than 1

but 2 is also greater than 1

Answer 17

so is 100, but lets use n=5 first

Answer 18

Oops my bad xD

Answer 19

if we look at teh bottom formula
h(5)= h(4)*B
if we look at the top formula
h(5) = 63*(-1/3)^5

Answer 20

so for the bottom formula, in order to know h(5), we need to know h(4)

Answer 21

?

Answer 22

ok, we want to solve for B right?

Answer 23

the equation that has B is
h(n) = h(n-1) *B only for n>1

Answer 24

now lets just look at h(n) = h(n-1)*B

if we choose n=5,
then
h(5) = h(5-1) *B

h(5) = h(4) *B

Answer 25

any questions?

Answer 26

Well how do I solve B then

Answer 27

didnt get there yet

Answer 28

ok now assuming we're just looking at h(n)=h(n-1) *B

this means that in order to know h(5) we need to know h(4)

if we wanted to solve for B

that means h(5) / h(4) = B

or h(n)/h(n-1) = B

Answer 29

do you understand this part?

Answer 30

so in order to determine B,

you need a nth term and the term before it

Answer 31

now, since we're dealing with geometric sequences, does what i mentioned above sound a little similar to the common ratio?

Answer 32

since in order to determine the next number in the sequence, you must multiply by the common ratio,

in order to go from the 4th term to the 5th term, we multiply by the common ratio, if we wanted to go from the 5th term to the 4th term, we divide by the common ratio

Answer 33

I still don't get it *facepalm*

Answer 34

ok, ill explain it another way then

but this time, using n=2 since 2 > 1

Answer 35

we look at the recursive defintion given

h(n)= h(n-1) *B

we substitute n=2

we get
h(2) = h(1) *B

Answer 36

in order to solve for B, we can divide by h(1) to both sides to get
B= h(2)/h(1)

Answer 37

Which is 2

Answer 38

what is h(2) and what is h(1)?

if we use the given equation
h(n)= 63*(-1/3)^n

Answer 39

or just 7

Answer 40

\[h(2)= 63*(-1/3)^2\]

Answer 41

just 7

Answer 42

h(1)=-21

Answer 43

right,
now
7/-21 = ?

Answer 44

-0.3

Answer 45

-1/3?

Answer 46

yea

Answer 47

so B=

Answer 48

-1/3

Answer 49

yup

Answer 50

Tysm <3

Answer 51

and notice how -1/3 is the common ratio in the first equation given

Answer 52

everytime you increase to the next term, n+1

you are multiplying by an additional -1/3