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Victoria had $200 in her account at the end of one year. At the first of each subsequent year she deposits $15 into the account
and earns 2% interest on the new balance, compounded annually. Which recursive formula represents the total amount of
money in Victoria's account at the end of the nth year?
a, - 1.02( a -1 +15), aq - 215
an - 15+1.02a -1, 2, - 215
2,- 1.02(an-1 +15); a, - 200
an = 15+1.02am-11 an - 200

Respuesta :

Answer:

The amount of money in Victoria's account at the end of n-th year will be,

$ [tex] (965 \times (1.02)^{(n -1)} - 765)[/tex]

Step-by-step explanation:

The amount of money in Victoria's account at the end of n-th year will be,

$ [tex](200\times (1.02)^{(n-1)} + 15 \times ((1.02)^{(n-1)} + (1.02)^{(n -2)} + (1.02)^{(n-3)} + ........ + (1.02)))[/tex]

= $ [tex](200 \times (1.02)^{(n -1)} + 15 \times \frac{1.02 \times ((1.02)^{(n-1)} - 1)}{0.02})[/tex]

= $ [tex](200 \times (1.02)^{(n -1)} + 15 \times 51 \times ((1.02)^{(n-1)} - 1))[/tex]

= $ [tex] (965 \times (1.02)^{(n -1)} - 765)[/tex]

Since, the interest is compounded over that $ 200 (which was there in the account at the end of 1st year) for (n-1) years and for (n-1) years, (n-2) years, (n -3) years, ...... 1 year respectively over those $ 15 which are deposited in the account at the end of 1 , 2, 3, ...... (n-1) years.

Answer:

[tex]a_{n}=\left [ a\left ( n-1 \right )+15 \right ]*1.02\\[/tex]

Step-by-step explanation:

1) A Recursive formula always makes reference to the previous term, written as a function.

2) From $200 to $215 there was a 7.5% growth, so since the question states that from the beginning of the second year there will be a regular growth.

3) Since it is 2% of interest compounded annually q=1+ 0.02.

[tex]A=215(1+\frac{0.02}{1})^{1}\\A=219.3[/tex]

Or simply

215*1.02=219.3

4) We can write a Recursive formula this way:

[tex]a(n)=215[/tex]

[tex]a(n)=a(n-1)(1.02)[/tex]

5) But since we have a pattern, She will deposit $15 yearly then we must make a little adjustment then add $15. to that. Considering the first term to be 200

[tex]a_{n}=\left [ a\left ( n-1 \right )+15 \right ]*1.02\\a_{1}=200[/tex]