need help with 2 complex numbers questions

[vagrant sun]

My brain is too small

Ah the zoom looks bad

I tried making qs into exponential form but stuck with e^(-pi/18)i and don’t know how to make it into cartesian form. While for q5, idk what i’m doing wrong but it doesn’t equal to zero when I add them.

[spare fractal]

For this one, any point in the form r(cos(x) + isin(x)) can be shown in polar form as (r,x) with r being radius and x being rotation counterclockwise
This equation mean’s you’re doing (1,3x)/(1,4x) or (1/1),(3x-4x) or (1,-x) which becomes 1(cos(-x) + isin(-x))

For 5B) could you show that OC = (OB)^3

[vagrant sun]

I was having trouble with changing the rotation into cartesian form because the angle was -10deg

[vagrant sun]

I tried to make a connection with 5a and 5b, but I can’t get them to add up and equal to zero for my working out

[spare fractal]

Could you atleast do a

[vagrant sun]

Yeah

I’ve done a