Section 11: Calculating With Complex Numbers 135
Example: Find the sum 2(cos 65° + i sin 65°) + 3(cos 40° + i sin 40°) and
express the result in polar form. (In phasor form, evaluate 265° +
340°.)
Keystrokes Display
| D
Sets Degrees mode for
any polar-rectangular
conversions.
2 v
2.0000
65 ´ V
2.0000
C annunciator displayed;
Complex mode activated.
´ ;
0.8452
Converts polar to
rectangular form; real
part (a) displayed.
3 v
3.0000
40 ´ V
3.0000
´ ;
2.2981
Converts polar to
rectangular form; real
part (a) displayed.
+
3.1434
| :
4.8863
Converts rectangular to
polar form; r displayed.
´ % (hold)
49.9612
θ (in degrees).
(release)
4.8863
Problems
By working through the following problems, you will see that calculating
with complex numbers on the HP 15c is as easy as calculating with real
numbers. In fact, once your numbers are entered, most mathematical
operations will use exactly the same keystrokes. Try it and see!
1. Evaluate:
2i −8 + 6i
3
4 −2
5i
2−4
5i