i

i Calculator (Imaginary Unit)

Calculate powers of i, convert between complex number forms, and explore imaginary numbers

Complex Number Calculator

Enter any integer (positive, negative, or zero)

Results

i1 = i
Powers of i of the form 4k+1 equal i

Pattern of Powers of i

i0 = 1
i1 = i
i2 = -1
i3 = -i
i4 = 1
Pattern repeats every 4 powers: i, -1, -i, 1, i, -1, -i, 1, ...

Example Calculations

Powers of i Pattern

i¹ = i
i² = -1
i³ = -i
i⁴ = 1
i⁵ = i
i⁶ = -1
i⁷ = -i
i⁸ = 1

Rule: i^n = i^(n mod 4)

Complex Number Example

Given: z = 3 + 4i

Magnitude: |z| = √(3² + 4²) = √25 = 5

Phase: φ = arctan(4/3) ≈ 53.13°

Polar form: z = 5e^(i × 53.13°)

Quick Reference

Definition of i
i = √(-1)
i² = -1
Powers of i Cycle
i¹ = i
i² = -1
i³ = -i
i⁴ = 1
Then repeats...
Complex Number Forms
Rectangular: a + bi
Polar: r × e^(iφ)
Trigonometric: r(cos φ + i sin φ)

Complex Number Properties

Magnitude
|a + bi| = √(a² + b²)
Phase Angle
φ = arctan(b/a)
Conjugate
conj(a + bi) = a - bi
Euler's Formula
e^(iφ) = cos φ + i sin φ

Understanding the Imaginary Unit i

What is i?

The imaginary unit i is defined as the square root of -1. While this might seem impossible with real numbers, i extends our number system to include complex numbers, which are essential in mathematics, physics, and engineering.

Key Properties

  • i = √(-1), therefore i² = -1
  • Powers of i follow a cycle of 4: i, -1, -i, 1
  • Complex numbers have the form a + bi
  • i enables solutions to equations like x² + 1 = 0

Applications

Complex numbers are used extensively in many fields including electrical engineering (AC circuits), quantum mechanics, signal processing, and computer graphics. They provide a powerful mathematical framework for describing oscillations and rotations.

Powers of i Pattern

i⁰ = 1
i¹ = i
i² = -1
i³ = -i
i⁴ = 1 (cycle repeats)

Rule: For any integer n, i^n = i^(n mod 4)

Key Formulas

Basic Operations

i = √(-1)
i² = -1
i³ = i² × i = -i
i⁴ = i² × i² = 1

Complex Number Conversions

|z| = √(a² + b²)
φ = arctan(b/a)
a = |z| cos φ
b = |z| sin φ