3. CHAPTER VII: Exponential and Logarithmic Functions and Complex Numbers
Learning
Outcome 1:
Defined and discussed Exponential
and Logarithmic Functions and
apply the laws to solve real life
problems..;
6. CHAPTER VII: Exponential and Logarithmic Functions and Complex Numbers
In mathematics, the logarithm is the inverse function
to exponentiation. That means the logarithm of a given
number x is the exponent to which another fixed
number, the base b, which must be raised, to produce
that number x. In the simplest case, the logarithm
counts the number of occurrences of the same factor in
repeated multiplication; for example,
1000 = 10 × 10 × 10 = 103
, the "logarithm base 10" of
1000 is 3, or log10(1000) = 3. The logarithm of x to base
b is denoted as logb (x).
9. CHAPTER VII: Exponential and Logarithmic Functions and Complex Numbers
Some applications of exponential function:
1. In the absence of factors affecting population growth, the
population after n years at a constant rate r is P(1 + r)n
. If the
population P is decreasing at a constant rate r, at the end of n
years the population would be P(1 – r)n
.
10. CHAPTER VII: Exponential and Logarithmic Functions and Complex Numbers
2. The half-life is the time it takes for half of a radioactive
element to decay. To find the amount Pn of the radioactive
substance with half-life k in n period of time, the formula to be
used is Pn = P(1/2)n/k
. The unit of k and n must be the same.
3. Compound interest behaves exponentially. This is explained
by its formula
A = P( 1 + r/m)tm
where A is the total amount after t years of investing the
principal amount P at r interest rate which is compounded m
times a year.