Day 42: November 5th
Objective: Apply strategies for finding inverses to
parent graph equations. Begin to think of the
inverse function for y=3x. THEN Define the term
logarithm as the inverse exponential function or,
when y=bx, “y is the exponent to use with base b to
get x.”
• Homework Check
• 6-54 to 6-58 (pgs 277-279)
• Wells Time
• 6-67 to 6-71 (pgs 281-282)
• Closure
Homework: 6-59 to 6-66 (pgs 279-280) AND 6-72 to
6-80 (pgs 283-284)
Project Due: Monday, November 8th
Silent Board Game
x8
g  x
32
1
2
1
4 3 64
16
3 5 1 0 4 2
x2 0
g  x
1
0.25
1
 2 
1.6
2 0.2
1
2
~ 2.3
g  x   log2  x 
1
8
6
3
Silent Board Game
x 1 0
g  x
1
8
0.2
  3
~ 2.3
1
0.25
2
1
 2 1 0
x2 3 4 8
g  x
1
1.6
2
1
2
16 32 64
2 3 4 5 6
g  x   log2  x 
6-71: Closure
log 7  49   2
log 3  81  4
  7
10   1.2
2   w + 3
7
log 5 5
log10
log 2
1.2
w 3
Logarithm's Undo Exponentials
Log’s give you exponents!
y2
Inverses
x
x2
y
Same as
y  log2  x 
Logarithm and Exponential Forms
y = log2(32)
y
2 = 32
Logarithms
This is the general form:
a b
log a b  x
x
a>0
b>0
The logarithm base a of b is the
exponent you put on a to get b.
i.e. Logs give you exponents!