Exponential Growth and Decay and Interest

Question 1

Exponential growth and decay

Answer 1

A = ka^2
A = amount
k = initial amount
a = depends on if it is growth or decay
When a > 1 exponential growth occurs
When 0 < a <1 exponential decay occurs

Question 2

Formula to calculate a in exponential growth

Answer 2

a = 1 + r/100
r = growth rate of r% per annum

Question 3

Formula to calculate a in exponential decay

Answer 3

a = 1 - r/100
r = decay rate of r% per annum

Question 4

Compound Interest

Answer 4

A = P(1+r/100)^n
P = amount of money borrowed or invested
r = the percentage applied to P in each investment period
n =number of periods investment occurs in
A = total amount of investment

Question 5

Interest formula

Answer 5

Interest = A - P
A = amount
P = principal