November 14, 2014
Unit F Logarithmic functions and their properties (A.4.A.)
Objective: To convert expressions from exponential form to logarithmic
form (and back again)
To solve logarithmic equations using rules of exponents.
November 14, 2014
Exponential Form: y=abx-h + k
Logarithmic Form: y = alogb(x-h) + k
**Exponentials and Logs are INVERSES!!
What are the functions we have learned to graph, so far??
Domain:
Range:
Domain:
Range:
Domain:
Range:
Domain:
Range:
Domain:
Range:
Domain:
Range:
November 14, 2014
Evaluating logarithms--w/out the calculator!!
SWIRL!
logarithmic form
logbase banswer=exponent
exponential form
bexponent=answer
logbx=y
log
=
What are the restrictions on ....
b=base
y=exponent
?
y
b =x
>0 and
?
>0
?
anything
=1
November 14, 2014
Change to Exponential Form:
1) log39=2
2) logx64=3
Now we will let's evaluate:
(find the value of x)
Change to Logarithmic Form:
4
3) 2 =16
3
4) 5 =125
Don't forget to SWIRL!
There are 3 types of equations to solve:
1) Variable is the exponent
2) variable is the base (base must be positive)
3) variable is the answer
5)
log232=x
6) log327=x
November 14, 2014
7) log5(
)=x
8) log2781=x
9) log
2
=x
November 14, 2014
10) logx3=2
11) logx64=
12) logx3=
November 14, 2014
13) log25x=1.5
14) log25(r2-11)=1
15) log2(q-3)=4
November 14, 2014
Homework: WS #1