What is the geometric interpretation of multiplying two complex numbers?

1 Answer
Dec 12, 2014

Let z_1z1 and z_2z2 be two complex numbers.

By rewriting in exponential form,

{(z_1=r_1e^{i theta_1}),(z_2=r_2 e^{i theta_2}):}

So,

z_1 cdot z_2 =r_1e^{i theta_1}cdot r_2 e^{i theta_2} =(r_1 cdot r_2)e^{i(theta_1+theta_2)}

Hence, the product of two complex numbers can be geometrically interpreted as the combination of the product of their absolute values (r_1 cdot r_2) and the sum of their angles (theta_1+theta_2) as shown below.

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I hope that this was clear.