29
Logs, natural logs and
e
The calculator uses
g
for log base 10 and
h
for log base
e
. You don’t have to
remember which button is which. All you need to do is look at the second function above
each button. The
g
button has
G
above it reminding you that the
g
button is base
10. Similarly the
h
button has
H
above it.
h
is base
e
.
1
Use your calculator to evaluate each expression correct to 3 decimal places.
A
10
log 105
B
log 8
e
C
10
log 0.6
D
log 0.5
e
E
(
)
10
log
4.3 2.5
´
F
4 log 209
e
2 A
Enter
( )
log
1
e
-
into your calculator.
B
Explain why your calculator displays the message “Math ERROR”.
3
Your calculator has two
e
buttons. You can find the value of
e
as the alpha
function on
K
. The value of
e
x
can be determined by using the second function
on
h
.
A
Determine the value of
e
using
Q K p
. Answer to 4 decimal places.
B
Find the value of
3
e
to 2 decimal places by pressing SHIFT
h3
.
1. Determine the following values correct to 2 decimal places.
A
2.5
e
B
1
e
-
C
e
4
Calculate the values of the following expressions.
A
2
log
e
e
B
3
log
e
e
C
log
e
e
D
1
log
e
e
-
F
10
log 100
G
1
10
log 10
-
5
What is the value of log
n
e
e
? (You’ll have to use your brain for this one!)
6
Evaluate
12
800
k
e
when
k
= 0.4. Express your answer to the nearest hundred.
7
Determine the value of
10
950
k
e
-
when
k
= 1.4.Express your answer in scientific
notation with 3 significant figures.
8
What is the value of
e
p
? Express your answer to 2 decimal places.
Answers
1A
2.021
B
2.079
C
0.222
-
D
0.693
-
E
1.031
F
21.369
2
log
x
only exists for
x
> 0.
3A
2.7183
B
20.09
4A
12.18
B
0.37
C
2.72
5A
2
B
3
C
1
D
1
-
E
2
F
1
-
6
n
7
97 200
8
4
7.90 10
-
´
9
8.54
© Sue Thomson and Shriro Australia PTY Limited. This page may be photocopied for classroom use.
