What is the complex number z=−4√3+4i represented in polar form?

A complex number in the form: z = a + bi  can be written in polar form as: z = r.e^i.theta, where r = √(a² + b²) and theta = tan^-1(b/a)  (that's arctan(b/a))

You should plug your numbers into these.

I notice the polar form sometimes seems to be written as  r.cis(theta)  which is r.cos(theta) + i.r.sin(theta)  (which I think is more like rectangular form!!).