Investment, logs and Geometric sequences Flashcards
What are 2 types of interests?
Simple and Compounded interest
What is simple interest?
tba
What is compounded interest?
TBA
What is the formula for annual compound interest ( the balance after n years?
Given an inital amount invested, what is the quarterely compound interest?
What is the formula for monthly compound interest?
What is the formula for weekly compound interest?
Lets say you invest £500 into a bank, that pays 12% interest per annum compounded quarterly, to find balance after a year what would it be?
The more frequently interest is compounded the what?
The higher the amount you get in a given year.
What is the general formula for compound interest over a given interval?
Say i invest 500 in a bank and they give interest per annum 12%, and it is compounded daily, what is the return i will get in a year and what is the return i will get in 4 years?
500(1+0.12/365)^365 = 563.7373078
500(1+0.12/365)^365 x 4 = 807.9734601
When m the amount of compound periods in a year gets larger and larger what happens?
the value of (1+r/m)^m gets closer to the expotential constant, e which is aproximately 2.7182818
When you are continously compounding, what is happening?
its changing every second, minute etc, like stock markets.
If the bank was to compound continously ( interest was compounded every instant, the balance in the bank at the end of one, 2 3 years would be what?
What is the general formula for compounding interest when you invest a certain amount in the bank?
If i invest 500 at 12% interest per annum with continous compounding what will be the balance after 2 years, 10 years?
500e^2x0.12 = 635.6245752
500e^10x 0.12 = 1660.058461
What are 4 problems involving interest rates?
1) How much do I invest
2) What is the interest rate
3) How long I need to invest
4) How often is the interest compounded m = compounding.
How much i need to invest?
How long do i need to invest to get a return of 1000 if i invest 500 at 12% interest per annum compounded annually?
As you can see using trial and error to solve investments can be time consuming, so what do we use?
We use logs
What is a key rule about logs?
What is the mulitplication rule for logs ( providing they have the same base) ?
What is the log division rule given the bases are the same ?
What is the log power rule?
What is a common log??
We usually use logs in base 10, where they are just denoted as log, called a common log