Complex Numbers |
Basic Definitions Algebraic Operations Complex Conjugation
The Complex Plane Complex Numbers in Polar Coordinate System The Euler Formula Trigonometric Applications Algebraic Applications
Complex Roots |
Complex Roots
In view of periodicity of trigonometric functions sine and cosine, a complex number can be rewritten in the polar form as follows: . The nth roots of z are determined by expression . By substituting m = 0, 1, 2, 3, ... we obtain all roots tm of a complex number. There exist n different roots exactly:
The next value of integer m gives the root tn+1 that coincides with t1:
Note that all roots have the same modulus , that is, they lie on the circle with the radius . There is a simple way to plot all n roots of a number z when one of the roots is known. We need only to divide the circle with radius into n equal parts, starting from the point on the circle that corresponds to a root of z. |