HP 25 User Manual

64 Function Keys
Solution:
Press Display
8.
25miiE] ~ 1 8 ~ .2 ~ 5 =~
I 05 a [1Og] ~ 1 2 ~ . 0 ~ 2 =~
B 16.23 Rating on Richter sca le.
Example 2: Ace explorer Jason Quarmorte is using an ordinary
ba rometer as an altimeter. After mea suring the sea level pres-
sure (30 inches of mercury) he climbs until the barometer indi-
cates
9.4 inches of mercury . Although the exact relationship of
pressure and altitude is a function of many factors , Qu a rmorte
knows that an approximation is given by the formula:
30 30
Altitude (feet) = 25,000 In---- = 25 000 tn--
Pressure ' 9.4
Where is Ja son Quarmorte ?
Solution:
Press
301m1m
9.4 8
a ~
25000
o
Display
130.00
13.
19
11. 16
125000 .
129012.
19
Altitude in feet.
Qu a rmorte is probably near the summit of Mount Everest
(29,028 ft).
Raising Numbers to Powers
a 0 permits you to raise a positive number (either an integer
or a decimal) to any power. For example , calculate 2
9
(i.e., 2 x
2
x 2 x 2 x 2 x 2 x 2 x 2 x 2).
Press
Display
2miiE]9 [ZJ
1512.00
Now find 8 - 1. 25(;7.
Press
Display
8miiE]
18.00
1.2567
rmJ a 0
10.07
In
conjunction with oo ,a [ZJ provide s a simple way to
extract roots. F or example, find the cube root of 5 (This is
equivalent to 5' /. ' ) ..

HP 25 Specifications

General

Power Source	Rechargeable battery pack
Programming Steps	49
Release Year	1975
Functions	Trigonometric, logarithmic, statistical
Type	Scientific
Dimensions	148 x 80 x 14 mm