Complex Number Multiplication and Division Calculator

Complex numbers:

z1 = a + bi, z2 = c + di

Real part (a):
Imaginary part (b):
Real part (c):
Imaginary part (d):
Re Im

Complex Number Multiplication and Division

What are Complex Number Multiplication and Division?

Complex number multiplication and division are operations performed on complex numbers, which are numbers in the form a + bi, where a and b are real numbers and i is the imaginary unit (i² = -1).

Formulas

For complex numbers z₁ = a + bi and z₂ = c + di:

Multiplication: \[z₁ × z₂ = (a + bi)(c + di) = (ac - bd) + (ad + bc)i\]

Division: \[\frac{z₁}{z₂} = \frac{a + bi}{c + di} = \frac{(ac + bd) + (bc - ad)i}{c^2 + d^2}\]

Calculation Steps

Let's multiply (3 + 2i) and (1 - 4i):

  1. Apply the multiplication formula:
    (a + bi)(c + di) = (ac - bd) + (ad + bc)i
  2. Substitute the values:
    (3 + 2i)(1 - 4i) = (3 × 1 - 2 × (-4)) + (3 × (-4) + 2 × 1)i
  3. Calculate:
    = (3 + 8) + (-12 + 2)i
    = 11 - 10i

Example and Visual Representation

Let's visualize the multiplication of (3 + 2i) and (1 - 4i):

Re Im z₁ = 3+2i r₁ = 3.61 θ₁ = 33.7° z₂ = 1-4i r₂ = 4.12 θ₂ = -76.0° z₁×z₂ = 11-10i (scaled) r = 14.87 θ = -42.3° Scale: 1:3

This visual representation shows:

  • The first complex number 3+2i in blue
  • The second complex number 1-4i in red
  • The result of multiplication 11-10i in green