Logarithmic And Exponential Functions; Logarithms - HP -67 Owner's Handbook Manual

Function Keys 103
36.5
77.8 77.8
@ &J Resistance R in ohms.
Reactance X, 46.28
ohms, available in
displayed X-register.
Logarithmic and Exponential Functions
Logarithms
The HP-67 computes both natural and common logarithms as well
as their inverse functions (antilogarithms):
0 is log. (natural log). It takes the log of the value in the
X-register to base e (2.718...).
8 is antilog, (natural antilog). It raises e (2.718...) to the power
of the value in X-register. (To display the value of e, press
18
is log;o (common log). It computesthe log ofthe value in the
X register to base 10.
8 is antilog;, (common antilog). It raises 10 to the powerof the
value in the X-register.
Example 1: The 1906 San Francisco earthquake, with a magnitude
of 8.25 on the Richter Scale is estimated to be 105 times greater
than the Nicaragua quake of 1972. What would be the magnitude
of the latter on the Richter Scale? The equation is:
R, =R, — log xz = 8.25 - (log 1(1)5 )
1
Solution;
Press Display
8.25
105 5
& Rating on Richter scale.