fra0102 Summary of Complex Numbers for Electronics Technology

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Subtracting Complex Numbers
Rectangular Form

This is the  formal expression for subtracting complex numbers:

(a + jb) (c + jd) = a - c + j(b - d)

 

The procedure for subtracting two complex numbers in rectangular form is fairly straightforward.

Here are two different complex numbers:

3 +j7 and 1 +j3

Here is how to show that the two values are to be subtracted:

(3 +j7) - (1 +j3)

To subtract these numbers, first subtract the real parts
(3 +j7) - (1 +j3):

3 - 1 = 2

Then subtract the imaginary parts
(3 +
j7) - (1 +j3):

j7 - j3 = j4

Putting together the real and imaginary parts:

2 + j4

So the overall result is:

(3 +j7) - (1 +j3) = 2 +j4

Learn From More Examples

  1. (3 + j4) - (1 +j2) = 2 + j2
  2. (4 +j8) - (3 +j3) = 1 +j5
  3. j4 - (3 +j2) = -3 +j2
  4. 4 - (1 +2j) = 3 -2j
  5. j3 - j2 = j
  6. (2 +j5) - (1 -j3) = 1 +j8
  7. (2 -j5) - (1 +j3) = 1 -j8
  8. (-1 +j2) - (3 +j4) = -4 -j2
  9. -j2 - (3 -j4) = -3 +j2
  10. (1 -j2) - (1 -j4) = j2

David L. Heiserman, Editor

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Revised: June 06, 2015