Complex Numbers 14 – Using De Moivres theorem to find more than one answer

You’ll learn

• Find all n roots of a complex number by adding 360°k (or 2πk) to the argument
• Apply De Moivre with a fractional power and iterate k = 0, 1, …, n−1
• Know when to generalise the angle: fractional powers (roots) only, never integer powers
• Check the roots form a regular n-gon evenly spaced on the Argand plane