Question

How do I write 1-2i in polar form? I know r=sqrt(5) and when using cos(theta), I find theta to be app. 63.43 and 296.57. However, when using sin(theta), I get an angle of -63.43?

Answer 1

So do I use the angle 63.43? I assume they are the same, just in different directions?

Answer 2

The angle is -63.43 degrees — the imaginary component of that number is negative, as seen in the diagram I drew.