136 Section 11: Calculating With Complex Numbers

Keystrokes

Display

2

´}

0.0000

8

“v -8.0000

6

´V

-8.0000

3 Y

352.0000

*

-1.872.0000

4 v

4.0000

5

¤

2.2361

2

“*

-4.4721

´V

4.0000

÷

-295.4551

2i. Display shows real part.

-8 + 6i. (-8 + 6i)3.

2i (-8 + 6i)3.

25 .

4 − 25i .

2i(-8 + 6i)3 . 4 - 2 5i

2 v5 ¤

2.2361

 

 

 

 

 

4 “*

-8.9443

 

 

 

 

 

´V

2.0000

 

 

 

2 − 4

5

i .

÷

9.3982

Real part of result.

´%

-35.1344

Answer: 9.3982 -35.1344i.

 

9.3982

 

 

 

 

 

 

2. Write a program to evaluate the

function ω =

2z + 1

for different

 

 

 

 

 

 

5z + 3

values of z. ( ω represents a linear fractional transformation, a class of conformal mappings.) Evaluate ω for z = l+2i.

(Answer: 0.3902 + 0.0122i. One possible keystroke sequence is: ´ b A v v 2 * 1 + ® 5 * 3 + ÷

¦´}n.)

3.Try your hand at a complex polynomial and rework the example on page 80. You can use the same program to evaluate P(z) = 5z4 + 2z3, where z is some complex number.

Load the stack with z = 7 + 0i and see if you get the same answer as before. (Answer: 12,691.0000 + 0.0000i.)

Now run the program for z = 1 + i. (Answer -24.0000 + 4.0000i.)