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anonymous
 5 years ago
Need help with difference equation...
anonymous
 5 years ago
Need help with difference equation...

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Suppose your car has a 14 gallon gas tank that you fill as soon as the level drops below half a tank. Every time you fill up, you add 1 quart (1/4 gallon) of an additive that mixes completely with the gas and is used along with the gas.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0What is the difference equation and initial value that models the amount A sub n of additive in the tank at the time of the nth fillup?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I attached so I will not have to type out entire problems

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0i see it. how much additive is remaining at the time of each fill up..

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I truly appreciate your help...I love getting on here helping others so I share your passion!

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0pistachios are more of my passion i think :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0this is more of a hobby lol

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0lol...well you're AWESOME!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok so do you understand the question

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0lets assume that we start with a clean tank..right? at halhway we fill it up and add the additive.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0at half a tank we have only half of what we put still in..... and the ration is the same, 14: .25 or some such right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the quart we put in becomes half a quart, and we add more gas and anouter quart... right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0this loks to be one of those exponential or log setups... from first glance

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0I could be wrong, I allow that :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0So A0 = 1 quart of additive. A1 = 1 quart + 1/2 thats left = 1.5 quarts a2 = 1.5/2 +1 and iterates that way...makes sense?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0lets plug in the numbers and see if theres a pattern to follow :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0would it be easier to stay with gallons since the tank is in gallons A1=.25+7?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0"that models the amount An of additive in the tank at the time" leads me to believe that the gas itself is of no consquence, only to tell us when to fill up again

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.01 = 1 2 = 1.5 3 = 1.75 4 = 1.875 5 = 1.9375 6 = 1.96875

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0i see a pattern emerging, just gotta put my finger on it :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0\[\frac{\frac{\frac{\frac{1}{2}+1}{2}+1}{2}+1}{2}+1...\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0Does this pattern remind you of anything?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0it does kinda look fibonaci like :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0i cant place it yet....

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0but its growing to a limit of 1.99999999999999999999

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Can you help with others/check

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes I have 1.998 for n=10

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0I can try; have you finished them?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Still have to answer rest of 2, almost done with 3, 4 completeeasy

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0the formula on p.368 is \[D _{n}=L(LD _{0})a ^{n}\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0and what do we do with this formula :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0c) Find the solution from a using equation

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0or maybe we use L =B/1a as n approaches infinity

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0have we found our difference equation yet?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I am using Asub n = .5Asub0 + 1

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0typed it earlier...do you agree?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0is that the same as .05(n) + 1?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0at n = 3 we get: 2.5 with that one, so it doesnt match our data.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0at any rate, we are adding 1 and a fraction, so anything over 2 is not correct :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0using previous values of Asubn to get others

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[A _{n}=.5A _{n+1}+1\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0lets test that equation and see if it gets us what we know. .5(3+1) + 1 = 2+1 = 3. its not working yet :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0I got something :) needs to be ironed out tho

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[A _{n+1}=.5A _{n}+1\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.02n+1 An = 1 +  2^n

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I see it but can't explain in formula correctly

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0\[1,\frac{1}{2}, \frac{3}{4}, \frac{7}{8}, \frac{15}{16}, \frac{31}{32}, \frac{63}{64}\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0that fits it to a "T" :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0\[A _{n} = 1+\frac{2n+1}{2^n}\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0its off at n=0; do we start at 0?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0that is giving greater than 2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0its close, but needs to be tweeked

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0\[A_{n} = 1 + \frac{2(n1)+1}{2^n}\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[A _{n}=.5A _{n1}+1\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0we are taking half of previous output and adding 1 right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0yours looks good like that :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0half of what it was, then add 1....yep

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0What is A_01? or are we starting n=1 :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0geeshhh. I had that thinking too hard ; (

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0good, we got an equation that we like...now we use it in C right? or B first

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0that was A; find the equation ;)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0B is; use it to make a table....

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0We just happened to make a table first lol

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0working backwards in a problem solving strategy ; )

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0Dn =L−(L−D0 )a^n So what does this formula mean? its greek to me :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0368 should tell us something about it...like what D is and L

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0B/1a in place of L for solutions growing towards infinity

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0sorry keep forgetting to his post

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0whats the chapter heading for your material?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Modeling with Difference Equations

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0does the formula have a name for it? its probably online somewhere and I can get a better grip on it.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0difference equation...

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0using Asubn+1=.5Asubn +1

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0we found a first order linear difference equation, if I see it right..

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0Tn+1 − Tn = k(Tn − S) looks useful Dn =L−(L−D0 )a^n but I dunno.... are there any other formulas on page 368?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[x _{n=}L+(x _{0}L)a ^{n}\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0used that in c got b working on e using L=B/1 to find limiting value

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the limit is 2 I beleive.... is that right? as n increases without bound we approach 2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes but trying to get that from equation...working backwards again

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0:) I plugged in alot of iteration in google and gets 2 :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0are we allowed to use the definition of a limt? f(n+h)  f(n)/h ?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0thats the limit as it approaches zero....not infiinity tho....

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0I think we would need a more rigid equation for that than just An=.5A(n1) + 1 tho, becasue there is no way to determine the value of A(n1) at any given point.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0unless you got a formula for that too :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0limit is to infinity ...it also states that n can be replaced by n1 to convert a forward difference equation to an equivalent backward de

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0.5 would change to a different number

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0forgot post button again

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0and for the last one; the size of the tank doesnt matter, its the ratio.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.016 gal filled every half is the same result

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0what about limiting value for f

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0id venture to guess that is it 2; but let me check my sources :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.01.666666666666666666666666666......

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0just got taht on cal!!!!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I have 3a and b can you check c for me Bsub15 = 80000(1.06)to the n  10,000 so

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0\[80000(1.06)n 10000\] looks good

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0\[B_n = 80000(1.06)(n1)  10000\]

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0at 1 that would be a balance of 10000; so prolly not

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[B _{n+1}=1.06B _{n}10000\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0noooo...you were about to make me scream!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so c I keep going back and forth on

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0well, if he keeps taking 10000 out, he runs outta money before then I think.

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.080000(1.06) = 84800  10000 = 74800 right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.079288  10000 = 69288

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.073445.28  10000 = 63445.28

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.067251.9968  10000 = 57251.9968

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.060687.116608  10000= 50687.116608 53728.34360448  10000 = 43728.34 46352.0404  10000 = 36352.0404

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0were running outta money :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.08th year: 38533.17  10000 = 28533.17 9th year: 30245.16  10000 = 20245.16 10th year: 21459.87  10000 = 11459.87 11th year: 12147.47 10000 = 2147.47 12th year: 2276.32  10000 ...... cant do it :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0lol...my 2 year was off by 1,000 wrote wrong digit from cal....geesh

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0year 12 shes broke... at 15 theres nothing left;

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0if anything she owes 37723.68 by year 15

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0so what amount can she withdraw each year that will result in a zero balance at year 15 is the question lol

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yeah i was just reading it again, too lmbo

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0its between 8000 and 9000 :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0between 8200 and 8300 :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0between 8230 and 8245

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0what would be my explanation...you working backwards

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0im just reiterating it 15 times on google and narrowing it down :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0once we get a number, we can plug it in and see if it works :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0same equation, just a different withdrawal amount

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0would we have to log this

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.08237 = 0.491505273 :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0 8 237.03 = 0.206773824 cant get any less  8 237.02 = 0.0259858751

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0explain how you got your answer: trial and error :)

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the way all good people have done it for thousands of years; we narrowed it down til something stuck

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I might add that, lol!

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0plug it into your calculator and see if it gets you a good deal...

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I will finish e bc I know you want to move on...THANKS SOOOO MUCH!
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