Complex Numbers with the Calculator
We will show how to perform basic complex numbers computations with the calculator
SHARP EL-520W.
We first need to put the calculator in complex numbers mode (CPLX) by doing the following.
.
MODE
.
.
=
bic
=
Let’s now enter the complex number 3 + 5i.
3
+
5
On the screen, we see 3. To see the imaginary part, we use
, once more we can go back to 3.
, to get the 5i. By pushing
By default, the calculator is in rectangular mode. To confirm this, we should see a little xy
on the top left of the calculator. To put the calculator in polar mode, we use rθ . We
should now see a little rθ on the top left. To go back to rectangular mode, use xy .
Let’s enter the polar complex number 56
30◦ .
b∠c
5
30
=
, to get the 30. By pushing
On the screen, we see 5. To see the angle, we use
once more we can go back to 5.
Example 1. Convert the complex number 3 + 4i into polar.
Solution: Enter 3 + 4i.
3
+
bic
4
=
Let’s convert it to polar.
rθ
, we get the angle 53.13◦ . The answer is then:
We see 5 and by pushing
53.13◦ .
56
Example 2. Convert the complex number 46
Solution: Enter 46
◦
60
60◦
into rectangular.
.
b∠c
4
60
=
Let’s convert it to rectangular.
xy
We see 2 and by pushing
, we get 3.464i. The answer is then:
2 + 3.464i.
Example 3. Evaluate (3 + 4i)(2 − 5i).
Solution:
(
3
+
bic
4
)
×
(
2
-
5
bic
, we get −7i. The answer is then:
We see 26 and by pushing
26 − 7i.
Example 4. Evaluate 26
◦
25
+ 56
◦
36
.
Solution:
2
b∠c
We see 6.97 and by pushing
25
+
5
b∠c
36
=
, we get 32.86. The answer is then:
6.976
Gilles Cazelais. Typeset with LATEX on May 21, 2014.
32.86◦
)
=
,