Question

PRECALC QUESTION:
Compute the modulus and argument of these complex numbers.

a. -5i
b. sqrt(10) (cos(5pi/7) +isin(5pi/7))

Answer 1

what is the modulus of a complex number?
what is the argument of a complex number?

Answer 2

i think the modulus is the aboslute value. and the book only told me that the argument is theta so im not sure what to do

Answer 3

@Loser66 modulus is distance from \(0\), i.e. absolute value. for example \(z=x+iy\) we have \(|z|=\sqrt{x^2+y^2}\)

Answer 4

@avanti for the argument, it's the angle with respect to the \(x\)-axis, so for \(z=x+iy\) we have: