HP 25 User Manual

Function Keys 59
Trigonometric Functions
Your HP-25 provides you with six trigonometric functions. It
also calculates angles in decimal degrees, radians, or grads; and
it
converts between decimal degrees and degrees , minutes,
seconds .
Trigonometric Modes
When the HP-25 is first turned ON , it " wakes up" with angles
specified
in decimal degrees. To set radians or grads mode,
press the III shift key followed by either ~ (radial1s) or ~
(grads). To switch back to the decimal degrees mode again,
press the IlIshift key followed by the ~ (d eg rees) key.
Note: 360 degrees = 27T radians = 400 grads
Functions
The six trigonometric functions provided by the calculator are:
D ~ (sine)
III ~ (arc sine)
D ~ (cosine)
III ~ (arc cosine)
D ~ (tangent)
1lI ~ (arc tangent)
Each trigonometric function assumes angles in decimal degrees,
radians,
or grads. Trigonometric functions are one-number
functions, so to use them you key in the number, then press the
function keys.
Example 1: Find the cosine of 35 °.
Press Display
35 !35. Calculator "wa kes up" in
decimal degrees mode.
D ~ ! 0.82 The a nswer.
Example 2: Find the arc sine in grads of .964.
Press
.964
1lI ~
1lI ~
Display
! 0.964
! 0.96
!82.87
Grads mode is set.
Grads.

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