Evaluating Log Expressions

9.6B - Logarithmic Notation Day 2

Write in log form.

 $4^2=16$  






 $6^{-2}=\frac{1}{36}$  

Multiple Choice

Rewrite in logarithmic form:

3⁴ = 81

• log₃4 = 81

• log₈₁3 = 4

• log₃81 = 4

• log₄81 = 3

Multiple Choice

Rewrite in logarithmic form:

(5+y)^3x = 125

• log _5+y 125 = 3x

• log _3x 125 = 5+y

• log _5+y 3x =125

• log₁₂₅ 3x = 5+y

Write in exponential form

 $\log_5125=3$  





 $\log_7\left(\frac{1}{49}\right)=-2$  

Multiple Choice

Rewrite in exponential form:

log₆36 = 2

• 2⁶=36

• 6²=36

• 36²=6

• 36⁶=2

Multiple Choice

Rewrite in exponential form:

log₂ 0.25 = -2

• -2² = 0.25

• -2^0.25 = 2

• 2^-2 = 0.25

• No correct answer

Multiple Choice

Rewrite in exponential form:
.

$$\log_{\left(x+3\right)}y=4$$  

• $$\left(x+3\right)^y=4$$  

• $$\left(x+3\right)^4=y$$  

• $$x^4=y$$  

• $$y^4=x+3$$   

Evaluating Logs

 $\log_4256$                                 $\log_2\left(\frac{1}{64}\right)$                               $\log_3-9$  

Multiple Choice

log₃81 =

• 2

• 3

• 4

• 5

Multiple Choice

log₄1 = 

• 0
• 1
• 4
• DNE

Multiple Choice

Evaluate.
log₆(¹/36)

• 2
• ¹/2
• -¹/2
• -2

Two Very Important Bases:

Recall: exponents and logs are inverse functions; they cancel each other's actions.
Simplify: 
 $\log_33^{5x}$  

 $\log_77^{5x^2+2x}$  

Last one...

Simplify: $\log_464^{2x}$