HP -22S Owner's Manual page 119

Example: Law of Cosines. A plane travels north for 175 miles be-
fore turning around. On the return trip, a strong wind from the east
pushes the plane 18° off course. After traveling 150 miles, how far is
the plane from the airport?
""'''''
Side a ---
N
I
Side b
- - - - - - - E
Airport
Two sides and the angle between them are known:
b
=
175
c
=
150
A
=
18°
By the law of cosines,
a
Keys:
• 1
MODES
I
{DG}
175.~
[!]
150.~G
2017501500
181cosl
0ffiJ
y(b
2
+
c
2
-2bc cos A).
Display:
Description:
Sets Degrees mode .
313,625.13131313 +
53,125.13131313-
--
-
52,51313.13131313X
x13.9511
Calculates cosine of
18°.
56.52132
Distance from airport.
8: Additional Examples 119