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Extracting DE question

  • Thread starter annoymage
  • Start date
  • #1
362
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Homework Statement



A recent graduate borrowed 19000$ at an annual rate of 5%
to buy a car from a bank. Suppose that it has made an arrangement to pay the bank
r $ per month. Let S(t), measured in $, be the balance due on the loan at ant time
t, measured in years.

Write a differential equation to calculate the amount of loan left to be
paid.

Homework Equations



n/a

The Attempt at a Solution



[tex]\frac{dS}{dt}[/tex] = [tex]\frac{S}{20}[/tex] - 12k

i think this is wrong because something is wrong when i do an explicite solution of S

e[tex]\frac{-t}{20}[/tex]S = 12k(1-e[tex]\frac{-t}{20}[/tex]) + 19000

defenitely something is wrong,

can someone help me how to translate or give some clue the question to

[tex]\frac{dS}{dt}[/tex] form,
 

Answers and Replies

  • #2
362
0
FYI, its e-t/20, sorry
 
  • #3
362
0
i've been told that.. bank usually are compound interest.... i dont know what that means
 
  • #4
30
0
looks like you have to submit the answer tomorrow, ait?

your answer should :
monthly repayments : RM 754.85
total interest payable : RM5290.92

where
loan amount = RM 40,000
interest rate = 5%
loan term = 5 yrs
repayments = monthly
repayments type = principal & interest

based on this calculator : http://www.banks.com.au/tools/calculator/loan-repayments/

come on BAGINDA, think faster.... huhuhuhu
 

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