Question

Could someone explain to me how, (De Moivre's Theorem) r(cosx + isinx) is in polar form? This makes no sense to me. At all. I thought polar form was in the form (r, θ), where R is the radius from the origin of some point and theta is the angle from the positive x-axis. I keep seeing the above referred to as in "polar form", but it seems nothing but.

Answer 1

r(cosx + isinx) is more often named as trigonometric form. But actualy there is no much difference with polar form since bouth parameters are present (r, θ), and it would work same way as polar form when aplying De Moivre's Theorem.

Answer 2

but I agree with you that the name polar form is not really aplyable to this one

Answer 3

Yeah. That was just confusing the living hell out of me. My textbook repeatedly referred to it as that, and nothing else on the internet I could find did, lol. Thanks.

Answer 4

yw