1. 5-2 Logarithms
What is a logarithm?

2. Can you find a pattern?

3. Please graph y = 2x
By plotting points

4. Now please graph the inverse
By plotting points
By plotting points

5. Here it is!
“logarithm” is the term for the inverse of any exponential function.
y = 2x  The inverse would be x = 2y
This is written officially as log2x = y

6. How to look at logarithms
logbx = y can be thought of as logbn = p
Then rewrite as n = bp (notice the significance of
the variables chosen!!)
And then solve it!

7. Some Rules n > 0 and p must be real. b ≠ 1
If logbx1 = logbx2 then x1 = x2
Logbb = 1
logb1 = 0
logbbx = x
7. blogbx = x

8. Examples Log525 2. Log3 logb16 = 2 4. logb = 5. log6x = -1
6. Find the inverse of log2(2x+4)