A few words about mathematics
Undoubtedly, everyone makes use of mathematical
One of the interests of
Mr. Y is 50000 Euro bank at 6%. We want to know how much it will ave the first year, second year, third year ...
By process of spontaneous calculations:
- First year: It will be the 50,000 Euro plus interest. To calculate interest by multiplying the percentage of 6% interest (ie 0, O6) by the amount deposited in the bank 50000 Euro, which will be: 50 000x0, 06 = 3000 Euro. So in total there will be at the end of the first year: 50,000 + 6% = 53,000 Euro x50000
- Second year: He will have the 53,000 plus interest calculated on the 53000, ie: 53000 + 6% = 56,180 Euro x53000
- The third year: 56,180 + 6% = 59,550.8 Euro x56180
So you see it's very tiring make these calculations, especially if you want to know how Mr. Y will be after 10 or 20 years for example. Well that's where
could well have a mathematical formula that allows us to calculate a time and at any time the principal amount plus interest earned.
Noting in general, C 0 is the amount of capital deposited at time 0 (today) so C n and the amount of capital available to the bank after the n th year and also note i = the interest rate.
- The first year we have: C = C 1 0 + C 0 x i = 0 C (1 + i)
- The second year we have: C 2 = C + C 1 1 x i = C 1 (1 + i) = C 0 (1 + i) (1 + i) = C 0 (1 + i) 2
....
- By inference, the n th years we have: C n = 0 C (1 + i) n
So it suffices to replace in this formula, n the number of years. For example, after the 20 th year, Mr. Y will ave 50000 (1 +6%) 20 = Euro 160,356.77.
This case seems more or less simple because it can easily happen to calculate, with a little patience, that Mr. Y strike at the end of the 20 th year. But if one asks a question such as: how can we calculate, for example, when Mr. Y reaches 100,000 Euro. mentally, it is impossible to calculate, but mathematically speaking, it is very simple. Just solve the equation C = C n 0 (1 + i) n No stranger to one that represents the number of years on the capital deposited in the bank. Here we asked when C n = 100000 So by replacing in formula (C n = 0 C (1 + i) n ) i by 6%, C No. 100000 and by C 0 by 50,000 we would have:
100000 = 50000 (1 +0.06) n
==> 1.06 n 100000/50000 =
==> 1.06 n = 2 To determine the value of n, we must use a function called the sign logarithm "ln" (because one of the characteristics and that this function lnx n = n . lnx)
==> LN1, 06 n = ln2
==> x n LN1, 06 = ln2
==> No = ln2/ln1, 06 = 11.895660996576
That is Mr. Y will be Euro 100,000 in the bank in 11 years , 0.895660996576x12m = 10 months and 22 days 0.747931958912x30j =
To check the answer, just replace n 11.895660996576 by the formula 50000 (1 +0.06) n and see if it gives good Euro 100,000.
This is a simple example to show you how important points is to use the formulas
In this blog, I would put more emphasis on calculations with bank loan explanations and practical examples.