construct a complex number in Python
num = complex(a, b) or num = a + bj
how to get the angle of the complex number in degrees, not radians?
np.degrees(np.angle(complex_num))
create the conjugate of pointB
np.conj(pointB)
extract the real component from the complex number in Python
np.real( num )
Euler’s formula

magnitude vs Euler’s formula

Fourier coefficient in general
the output of the Fourier transform
Fourier coefficient vs Euler’s formula
abs(complex) = magnitude
angle(complex) = phase
Fourier components are complex numbers

all cosines are in-phase - how would this look like? what does it mean?
they all start at 1. At some time point, they are all 1 again. This occurs at 1s.
