HP 25 User Manual

formula to calculate the great circle distance that Odysseus
must sail in order to court her.
Distance = COS- I [ sin (LAT ,) sin (LAT
d
)
+
cos (LAT,) cos (LAT
d
) cos
(LNG
d
-
LNG
s
) ] x 60.
Where LAT s and LN G
s
= latitude and longitude of the
source (Tristan
da Cunha).
LATd and
LNG
d
= latitude and longitude of the
destination.
Solution: Convert a ll degrees, minutes, seconds entr ies into
decimal degrees as you key them
in . The equation for the great
circle distance from Tristan da Cunha to the nearest inhabited
land is:
Distance = COS-I [ s in (37°03') sin (15 °55') +
cos (37° 03') cos ( 15 °55') cos (5 °43'W - 12 ° 18 'W) ] x 60
Press
Display
0. 00
0.00
5.43 11 @ 5.72
12. 18 II @ El 1;= - ~ 6. ~ 58 ~ ===;
O ~ 1 0. 99
15 . 55 1I @ 1lmJ1 F= I = 1 5 == . 9 ~ 2 = =:
o ~ 1 0.96
~ === = =:
o i=1 = 0 = . 9 = 6 ==~
37.0311@ 1lmJ0 1 37 . 05
O ~ 1 0. 80
o 1 i== 0. ~ 76 ~~
1m 00 ~ I 0. 60
_ 1 0 ~ :=1 =0.=2=7 ====i
o i=1 = 0 . = 1 = 7 == ~
El 1 0.93
II ~ ~I ~ 2 ~ 1 ~ .9 =:' 2 = =:::;
60
0 1 1315.41
Display mode is set.
(Assumes no results remain
from previous example.)
Sets decimal degree mode for
trigonometric functions.
Distance in nautical miles that
Odysseus must sa il to visit
Penelope.

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