Question

Express the complex number in trigonometric form.

-4

Answer 1

Since complex numbers have a real and imaginary part that looks like it's on a triangle, we have this way of showing them in polar coordinates:

cos(x)+i*sin(x).

Since there's no imaginary part to -4, we know that x=pi so that it's negative and we multiply it by 4 to make it stretch out past the radius 1 of the unit circle:

4[cos(pi)+i*sin(pi)]