Question

Multiplication of a non-zero complex number by i rotates it through

Answer 1

Answer:

90 degrees in an anticlockwise direction

Step-by-step explanation:

Look at what happens you multiply 1 by i... it goes to i.

In general, a+bi multiplied by i is

( a + bi ) i = ai + (bi)i = ai - b = -b + ai.

So what was the horizontal coordinate, becomes the vertical coordinate, and what was the vertical coordinate gets its sign changed and becomes the horizontal coordinate.  This describes a rotation by 90 degrees.