The polar form of a nonzero complex number 
expresses 
in terms of the polar coordinates 
of the point 
as
 |
where 
is the complex
modulus and 
is a complex argument. The latter is defined
only modulo 
.
Choosing a specified interval gives a principal argument.
In polar form, complex multiplication multiplies
complex moduli and adds complex
arguments.
The expression 
is also called exponential form and follows from
the Euler formula. The expression 
is called rectangular form,
with real part 
and imaginary part 
. The term exponential
form is also used for equations such as 
that are equivalent to logarithm
equations, a distinct usage (Abramson 2021).
