find the standard form of the complex numbers 5/4 (cos 225degree + isin 225degree)

5/4(cos225 + isin225) =

1.25(-0.7071 - i0.7071) =
-0.8839 - i0.8839 =
tanA = -0.8839 / -0.8839 = 1,
A = 45 deg. = 45 + 180 = 225 deg, Q3.
Since the X and Y components are neg,
our resultant vector is in Q3.

r = -0.8839 / cos45 = -1.25 @ 225 deg,
Q3.