HP HP-67

Function Keys 93
Trigonometric Modes
For trigonometric functions, angles can be assumed by the calculator
to be in decimal degrees, radians, or grads. When the HP-67 is first
turned ON, it ‘‘wakes up’’ with angles assumed to be in decimal
degrees. To select radians mode, press (3 (radians) before using
a trigonometric function. To select grads mode, press [ (grads).
To select decimal degrees again, press [ (degrees).
Note: 360 degrees = 400 grads = 27 radians
Functions
The six trigonometric functions provided by the calculator are:
(1] (sine)
8 (arc sine)
08 (cosine)
8 (arc cosine)
@ (tangent)
a (arc tangent)
Each trigonometric function assumes that angles are in decimal
degrees, radians, or grads, depending upon the trigonometric mode
selected.
All trigonometric functions are one-number functions, so to use them,
you key in the number, then press the function key(s).
Example: Find the cosine of 35°.
Press Display
35
B
3
The HP-67 ‘‘woke up’’ in degrees mode when you first turned it ON.
Example 2: Find the arc sine in radians of .964.
Press Display
Q Selects radians mode.
(Results remain from
previous example.)
.964 .964
a Radians.