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Complex Number Operations

This calculator helps you perform basic arithmetic operations—addition, subtraction, multiplication, and division—on complex numbers. Just input the real and imaginary parts of two complex numbers, and get instant results.

e.g., 2 for 2 + 3i

e.g., 3 for 2 + 3i

e.g., 1 for 1 - 2i

e.g., -2 for 1 - 2i

How it works

This calculator helps you perform basic arithmetic operations—addition, subtraction, multiplication, and division—on complex numbers. Just input the real and imaginary parts of two complex numbers, and get instant results.


The Formula
Let z₁ = a + bi and z₂ = c + di. Addition: z₁ + z₂ = (a + c) + (b + d)i
Subtraction: z₁ - z₂ = (a - c) + (b - d)i
Multiplication: z₁ * z₂ = (ac - bd) + (ad + bc)i
Division: z₁ / z₂ = [(ac + bd) / (c² + d²)] + [(bc - ad) / (c² + d²)]i (where c² + d² ≠ 0)

Worked Example
  1. Example: Multiply (2 + 3i) by (1 - 2i)

    To multiply z₁ = 2 + 3i and z₂ = 1 - 2i: Input '2' for Real Part (z₁), '3' for Imaginary Part (z₁). Input '1' for Real Part (z₂), '-2' for Imaginary Part (z₂). The calculator will show: Multiplication: (2*1 - 3*(-2)) + (2*(-2) + 3*1)i = (2 + 6) + (-4 + 3)i = 8 - i


Tips, Assumptions & Limitations
  • Enter the real and imaginary parts as numbers. Decimals and negative values are allowed.
  • The imaginary unit 'i' is automatically handled; just input its coefficient.
  • For division, ensure the denominator (second complex number) is not zero.
FAQ

A complex number is a number that can be expressed in the form 'a + bi', where 'a' and 'b' are real numbers, and 'i' is the imaginary unit, satisfying the equation i² = -1. 'a' is called the real part, and 'b' is called the imaginary part.

Complex numbers are crucial in many fields, including electrical engineering (for analyzing alternating current circuits), quantum mechanics, signal processing, and fluid dynamics. They allow us to solve equations that have no real solutions, such as x² + 1 = 0.

To add or subtract complex numbers, you simply add or subtract their corresponding real parts and imaginary parts separately. For example, (a + bi) + (c + di) = (a + c) + (b + d)i, and (a + bi) - (c + di) = (a - c) + (b - d)i.

To multiply complex numbers (a + bi) and (c + di), you use the distributive property (similar to multiplying binomials) and remember that i² = -1. The formula is (ac - bd) + (ad + bc)i.

Dividing complex numbers involves multiplying the numerator and denominator by the conjugate of the denominator. If you have (a + bi) / (c + di), you multiply both by (c - di) to eliminate 'i' from the denominator. The general formula is [(ac + bd) / (c² + d²)] + [(bc - ad) / (c² + d²)]i.

Companion article

Complex Number Operations Explained: Add, Subtract, Multiply, Divide

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