ib maths sl logarithms definition
TRANSCRIPT
Logarithms
By the end of the lesson you will be able to :
• Understand what a logarithm is.
• Find logarithms of numbers in different bases.
• Use logarithms to rewrite exponential expressions.
Solve the equations:
3x =3 (7x+6)2
2x = 5
Logarithms will help us to solve these type of equations.
In the previous equation, , 8 can be expressed as a power of 2. But that is not the case with 5.
Definition:
( a > 0, a ≠1 )
log2 8 = 3 because 23=8
log10 100 =
log2 32 =
log3 27 =
log10 0.1 =
log7 1=
log4 2 =
log5 0.2 =
log10 1 =
Write these powers as logarithms:
43 = 64
102 =0.01
Basics:
log2 2 = log7 7 =
loga a = 1
log7 1 = log4 1 =
loga 1 = 0
log 4 0 = loga 0 not possible
log10 is written log
Solve worksheet : "Understanding logarithms"
http://www.mathsbingo.com/A%20enviar/LogarithmsDetermine/LogarithmsDetermine.html
Solve Book page 5455 Ex 2D