Graph z = 3cos315° + 3isin315° in the complex plane, how do I explain where I would find this equation on a complex plane?

\(\cos(315^\circ) = \dfrac{\sqrt{2}}{2}\\ \sin(315^\circ) = -\dfrac{\sqrt{2}}{2}\\ z=\dfrac{3\sqrt{2}}{2} - i \dfrac{3\sqrt{2}}{2}\\ \text{now just apply the results of the last problem}\)