HP HP-28S - Page 86

• R- P (rectangular-to-polar) converts a complex number in rectangu-
lar notation (x, y) to polar notation (r, 0).
• P-R (polar-to-rectangular) converts a complex number in polar no-
tation (r, 0) to rectangular notation (x, y).
• ABS (absolute value) returns r for a complex argument (x, y).
• NEG returns (- x, - y) for a complex argument (x, y).
• ARG returns 0 for a complex argument (x, y).
Note that only P-R interprets a complex number as polar coordinates;
all other functions-arithmetic, trigonometric, logarithmic, hyperbolic,
and so on-interpret a complex number as rectangular coordinates.
Remember this important rule: Any complex number in polar coordi-
nates must be converted to rectangular coordinates before you can use it
in a calculation.
As an example of arithmetic with polar coordinates, suppose you
travel 2 miles at a bearing of 36°, then 3 miles at a bearing of 65°.
What is the resulting distance and bearing, calculated to two decimal
places?
Select Degrees
angle mode and FIX 2 number display .
• 1 MODE I DEG 2 F I X 3: (25. 001.35. 00)
2: (0.0~,2.00)
1: (1.57,-1.32)
RillIiD_o::aGm~
Enter the first distance and bearing.
~----------~~~~~~~
CD 2 GJ 36 2: (0.00,2.00)
1: (1.57,-1.82)
Convert to rectangular coordinates .
• 1 COMPLX II NEXT I P+R
(2,360
RillIiD_o::aGm~
3: (0.00,2.00)
2: (1.57 -1.32)
1 : ( 1. 62, 1. 18)
DlIIGmlI:lIBCIBI'i1B_
Enter the second distance and bearing.
CD 3 GJ 65 =2-: -----:-( -:-1.-=5=7"""1. --1"-.-=3-=-2""")
1 : ( 1. 6<:::, 1. 18)
(3,650
DlIIGmlI:lIBCIBI'i1B_
6: Complex-Number Functionns 85