Simple operations with complex numbers – HP 49g+ User Manual

Page 74

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The result shown above represents a magnitude, 3.7, and an angle
0.33029…. The angle symbol (

) is shown in front of the angle measure.


Return to Cartesian or rectangular coordinates by using function RECT
(available in the catalog,

‚N). A complex number in polar

representation is written as z = r

e

i

θ

. You can enter this complex number into

the calculator by using an ordered pair of the form (r,

∠θ

). The angle symbol

(

) can be entered as

~‚6. For example, the complex number z =

5.2e

1.5i

, can be entered as follows (the figures show the RPN stack, before

and after entering the number):

Because the coordinate system is set to rectangular (or Cartesian), the
calculator automatically converts the number entered to Cartesian coordinates,
i.e., x = r cos

θ

, y = r sin

θ

, resulting, for this case, in (0.3678…, 5.18…).


On the other hand, if the coordinate system is set to cylindrical coordinates
(use CYLIN), entering a complex number (x,y), where x and y are real
numbers, will produce a polar representation. For example, in cylindrical
coordinates, enter the number (3.,2.). The figure below shows the RPN stack,
before and after entering this number:

Simple operations with complex numbers

Complex numbers can be combined using the four fundamental operations
(

+-*/). The results follow the rules of algebra with the caveat that

i

2

= -1. Operations with complex numbers are similar to those with real

numbers. For example, with the calculator in ALG mode and the CAS set to
Complex, try the following operations:

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