Divide Complex Numbers Calculator

Calculate the division of two complex numbers in rectangular or polar form

Complex Number Division

Dividend (Z₁)

Current Z₁: 4+3i = 5.000000×e^(i36.869898°)

Divisor (Z₂)

Current Z₂: 2+i = 2.236068×e^(i26.565051°)

Division Results: Z₁ ÷ Z₂

Rectangular Form
2.2+0.4i
Polar Form
2.236068×e^(i10.304846°)

Step-by-Step Solution (Rectangular Form)

Given: Z₁ = 4 + 3i, Z₂ = 2 + 1i

Formula: (a + bi) ÷ (c + di) = [(ac + bd) + i(bc - ad)] ÷ (c² + d²)

1. Calculate ac = 4 × 2 = 8

2. Calculate bd = 3 × 1 = 3

3. Calculate bc = 3 × 2 = 6

4. Calculate ad = 4 × 1 = 4

5. Numerator real part: ac + bd = 8 + 3 = 11

6. Numerator imaginary part: bc - ad = 6 - 4 = 2

7. Denominator: c² + d² = 2² + 1² = 5

8. Real part: 11 ÷ 5 = 2.200000

9. Imaginary part: 2 ÷ 5 = 0.400000

Result: 2.2+0.4i

Polar Form Division (Much Simpler!)

Formula: |Z₁|e^(iφ₁) ÷ |Z₂|e^(iφ₂) = (|Z₁|/|Z₂|)e^(i(φ₁-φ₂))

1. Divide magnitudes: |Z₁|/|Z₂| = 5.000000/2.236068 = 2.236068

2. Subtract phases: φ₁ - φ₂ = 36.869898 - 26.565051 = 10.304846°

Result: 2.236068×e^(i10.304846°)

Magnitude
2.236068
Phase
10.304846°
Conjugate
2.2-0.4i

Example Problems

Example 1: Basic Complex Division

Problem: Divide (4 + 3i) ÷ (2 + i)

Solution:

• Using formula: (a + bi) ÷ (c + di) = [(ac + bd) + i(bc - ad)] ÷ (c² + d²)

• ac + bd = 4×2 + 3×1 = 8 + 3 = 11

• bc - ad = 3×2 - 4×1 = 6 - 4 = 2

• c² + d² = 2² + 1² = 4 + 1 = 5

Answer: (11 + 2i) ÷ 5 = 2.2 + 0.4i

Example 2: Division by Pure Imaginary

Problem: Divide (3 + 4i) ÷ 2i

Solution:

• Multiply by conjugate: (3 + 4i) × (-2i) ÷ [2i × (-2i)]

• Numerator: (3 + 4i) × (-2i) = -6i - 8i² = -6i + 8 = 8 - 6i

• Denominator: 2i × (-2i) = -4i² = 4

Answer: (8 - 6i) ÷ 4 = 2 - 1.5i

Example 3: Polar Form Division

Problem: Divide 5e^(i60°) ÷ 2e^(i30°)

Solution:

• Divide magnitudes: 5 ÷ 2 = 2.5

• Subtract phases: 60° - 30° = 30°

Answer: 2.5e^(i30°) = 2.5(cos30° + i sin30°) ≈ 2.165 + 1.25i

Division Formulas

Rectangular Form

z₁/z₂ = [(ac+bd) + i(bc-ad)]/(c²+d²)

Multiply by conjugate of denominator

Polar Form

|z₁|e^(iφ₁) ÷ |z₂|e^(iφ₂) = (|z₁|/|z₂|)e^(i(φ₁-φ₂))

Divide magnitudes, subtract phases

Special Cases

• 1/i = -i

• z/z* = |z|²

• z/1 = z

Key Properties

🚫

Division by Zero

Cannot divide by 0 + 0i

🔄

Conjugate Method

Multiply by conjugate of denominator

📐

Polar Advantage

Much simpler in polar form

↔️

Inverse Operation

Division is inverse of multiplication

Understanding Complex Number Division

What are Complex Numbers?

Complex numbers extend the real number system by including the imaginary unit i, where i² = -1. They can be represented in rectangular form (a + bi) or polar form (r×e^(iφ)), where r is the magnitude and φ is the phase angle.

Division Methods

There are two main approaches to dividing complex numbers: the conjugate method for rectangular form and the magnitude/phase method for polar form. The polar method is generally simpler and more intuitive.

Applications

  • Electrical engineering (AC circuit analysis)
  • Signal processing and communications
  • Quantum mechanics and physics
  • Control systems engineering

Mathematical Foundation

Complex Conjugate

The key to rectangular division is multiplying by the complex conjugate:

z̄ = a - bi (conjugate of a + bi)

This eliminates the imaginary part in the denominator.

Polar Form Advantage

In polar form, division becomes much simpler:

  • • Divide the magnitudes
  • • Subtract the phase angles
  • • No complex algebra required!

Division Properties

  • 1. |z₁/z₂| = |z₁|/|z₂|
  • 2. arg(z₁/z₂) = arg(z₁) - arg(z₂)
  • 3. (z₁/z₂)* = z₁*/z₂*
  • 4. z/z̄ = |z|²