What is the polar complex form of a wave with amplitude and phase?

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desklamp2
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Homework Statement


What is the amplitude and phase of the complex function?

f(t) = (1-2i)e^(iwt)

Homework Equations


None/unknown
Normal Polar Form = Real*e^imaginary
i = e^pi/2*i

The Attempt at a Solution



[/B]I am trying to bring this into a normal polar form to easily see the phase and amplitude.

I have got e^iwt - 2e^i(wt+pi/2)

But now I do not know how to combine these two expressions to make 1 wave?
 
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Try to rewrite [tex]1-2i[/tex] as [tex]A\exp(i B)[/tex]
 
1 - 2i = √5 [cos (11 ⋅ pi / 12) + i sin (11 ⋅ pi / 12)] = √5 e^[i(11 ⋅ pi / 12)]

f(t) = (1-2i) [e^(iwt)]

f(t) = √5 e^[i(11 ⋅ pi / 12)] ⋅ [e^(iwt)]

f(t) = √5 e^i[11 ⋅ pi / 12 + wt]

f(t) = √5 [cos ((11 ⋅ pi / 12) + wt)] + i √5 [sin ((11 ⋅ pi / 12) + wt)]

Re[f(t)] = √5 [cos ((11 ⋅ pi / 12) + wt)]

Amplitude: √5

Phase: (11 ⋅ pi / 12) + wt

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Örsan Yüksek
 
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