HP HP-65 - Functions Involving Angles; Angular Mode

Using this rule and common sense, you may have already cal-
culated several functions effectively. Missing from the presenta-
tion thus far, has been a systematic review of just which functions
are available, and the respective conditions that apply to them
individually. To meet this need, all essentials are included in
Figures 3-1, 3-2, and 3-3.
To calculate a given function, the respective table entry shows
any conditions that apply to the input value(s), the keys to use,
and conditions applying to the result(s). If your need is to start
calculation immediately, you might even end your study of func-
tions with the tables, skipping the sample cases.
Functions Involving Angles
These functions are listed in Figure 3-1. They include the
trigonometric functions (sine, cosine, tangent and their inverses),
the rectangular-polar conversions, the addition and subtraction
of angles expressed in degrees, minutes, seconds, and conversions
of angles expressed decimally' to/from degrees, minutes, and
seconds.
Angular Mode
Operations involving angles assume the angles to be expressed in
units of the prevailing angular mode, which is set to decimal
degrees whenever the calculator is switched on. You can set the
mode to radians or grads or decimal degrees by using the mode
functions.
Angular Mode Functions
Keys Function
. Set mode to grads
. Set mode to radians
. Set mode to degrees
400 grads = 360 degrees = 2 T radians
Keys to which Angular Mode applies:
(W] [cos| [mN) [R+F) [>DMmS]
In the examples, the degree mode is assumed except as noted otherwise.