What is the polar form of the complex number 6-4i ?

A complex number a + ib can be written in the polar form
r*cis A where r is the absolute value of the complex number or sqrt (a^2 + b^2) and A  =
arc tan (y/x)

Here we have z = 6 -
4i.

r = sqrt (6^2 + 4^2) = sqrt (36 + 16) = 2*sqrt
13

A = arc tan (-4/6) = arc tan (-2/3) = -33.69
degrees

The polar form of the complex number
is 2*sqrt 13 cis -33.69