Natural Logs and Sigma Notation
Natural Logarithms:
e1 = 2.71828........ (irrational)
ln (natural logarithm) is used to represent log e
ln 1 means ex = 1
ln e means....
so ln 1 =
So ln e =
Ex. Find ln5
Ex. Solve ex = 6
Ex. Solve ex = 8
**Mathematicians find it useful to express the equations of
different exponential functions using the same base ( e).
Ex. Using P = 2.28(1.014) n Rewrite using base e.
Ch2(II) Logs Page 1
Note: 0.014 is the growth rate, this is why base e is
commonly used with growth/decay.
Assignment: p141 #1-3, 5a, 7-9, (10 bonus)
Sigma Notation:
The symbol Σ represents sum. (Greek S)
Ex. The series 5 + 10 + 20 + 40 + 80 + 160 can be written...
Ex. Evaluate
Ch2(II) Logs Page 2
Ex. Evaluate
Ex. How many terms are in the sum
Assignment: p132 #1-5
Quiz next class
Ch2(II) Logs Page 3