- #1

Mentallic

Homework Helper

- 3,798

- 94

## Main Question or Discussion Point

When given a complex number [itex]z=x+iy[/itex] and transforming this into its mod-arg form giving [itex]rcis\theta[/itex] where [itex]r=\sqrt{(x^2+y^2)}[/itex] and [itex]\theta=arctan(y/x)[/itex], we are assuming that [itex]-\pi/2<\theta<\pi/2[/itex].

What if however a student is asked to convert the complex number -1-i into mod-arg form? If they just start to plug-and-chug they'll quickly end up with the result [itex]\theta=\pi/4[/itex] and all of a sudden they've changed the complex number into it's negative, 1+i.

How does one avoid this dilemma?

What if however a student is asked to convert the complex number -1-i into mod-arg form? If they just start to plug-and-chug they'll quickly end up with the result [itex]\theta=\pi/4[/itex] and all of a sudden they've changed the complex number into it's negative, 1+i.

How does one avoid this dilemma?