HP HP-67

118 Function Keys
Press Display
o The new standard
deviation for age is now
available in X-register
for use.
Vector Arithmetic
You can use your HP-67 to add or subtract vectors by combining the
polar/rectangular conversion functions (the ?) and £ keys) with the
summation functions (the and Z-] keys).
Example: Grizzled bush pilot Apeneck Sweeney’s converted
Swordfish aircraft has a true air speed of 150 knots and an estimated
heading of 45°. The Swordfish is also being buffeted by a headwind
of 40 knots from a bearing of 25°. What is the actual ground speed
and course of the Swordfish?
Method: The course and ground speed are equal to the difference of
the vectors. (Notice that North becomes the x-axis so that the
problem corresponds to navigational convention.)
150 Knots 40 Knots