Question

#complexification of sinusoidale function.

we have y=kcos(wt)
we get y^~ = (k/(iw+k)) e^iwt

Then prof speaks abt going polar or carthesian.

Then he makes a geomtric interpretation of the equation when one goes polar.
I don t understand this explanation.
Please help

Answer 1

You will need to review polar co-ordinate system since you can see that you have an "imaginary" number in the transition your professor made from:
\[y = \cos(wt)\]

This may help to understand that:
http://mathworld.wolfram.com/PolarCoordinates.html