MathematicsComplex NumbersA-Level
GCE A-LevelAbiturAPAQABaccalauréat GénéralBachilleratoCambridgeCAPS

Argument of Complex Number Calculator

Calculate the angle of a complex number.

Use the free calculatorCheck the variablesOpen the advanced solver
This is the free calculator preview. Advanced walkthroughs stay in the app.
Result
Ready
Argument (Rad)

Formula first

Overview

The argument of a complex number is the angle formed between the positive real axis and the vector representing the number in the complex plane. This value is a crucial component for converting complex numbers from Cartesian coordinates (a + bi) into polar or exponential forms.

Symbols

Variables

a = Real Part, b = Imaginary Part, = Argument (Rad)

Real Part
Variable
Imaginary Part
Variable
Argument (Rad)
rad

Apply it well

When To Use

When to use: This formula is used whenever you need to determine the direction of a complex number relative to the origin. It is a prerequisite for calculations involving De Moivre's Theorem, such as finding the powers or roots of complex values.

Why it matters: In electrical engineering and physics, the argument represents the phase shift of a waveform. It allows professionals to quantify the timing offset between voltage and current in AC circuits or to analyze frequency responses in signal processing systems.

Avoid these traps

Common Mistakes

  • Degrees vs Radians.
  • Wrong quadrant (adding Ϭ).

One free problem

Practice Problem

Calculate the argument 't' in degrees for a complex number with a real part a = 5 and an imaginary part b = 5.

Real Part5
Imaginary Part5

Solve for:

Hint: When the real and imaginary components are identical and positive, the vector bisects the first quadrant.

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. Wikipedia: Argument (complex analysis)
  2. Britannica: Complex number
  3. Stewart, James. Calculus: Early Transcendentals.
  4. Halliday, Resnick, and Walker, Fundamentals of Physics
  5. Wikipedia: Radian
  6. Complex Variables and Applications, 9th ed. by James Ward Brown and Ruel V. Churchill
  7. AQA Further Mathematics — Core Pure (Complex Numbers)