Vout = (a+jb)Vin, what do A and B stand for?

[ConfusedBrendan]

Homework Statement

I was given a graph with two waves on it, the input and output wave. I found the frequency of the waves, change in magnitude and change in phase. The last question asks me to write the transformation from input to output as a phasor and he gave the relevant equation below.

Vout = output voltage, Vin = input voltage, j is i or the square root of -1, and I don't know what A and B stand for

Homework Equations

Vout = (a+jb)Vin

The Attempt at a Solution

I solved the change in amplitude = 0.7 and the change in phase is -13.3 degrees

 

[axmls]

Do you know how to convert a magnitude and an angle to a complex number?

It would also help to see the graph.

 

[rude man]

Homework Statement

I was given a graph with two waves on it, the input and output wave. I found the frequency of the waves, change in magnitude and change in phase. The last question asks me to write the transformation from input to output as a phasor and he gave the relevant equation below.

Vout = output voltage, Vin = input voltage, j is i or the square root of -1, and I don't know what A and B stand for

Homework Equations

Vout = (a+jb)Vin

The Attempt at a Solution

I solved the change in amplitude = 0.7 and the change in phase is -13.3 degrees

There is a widely known relation changing a + jb to ρ exp(jφ) where ρ is magnitude and φ is phase. Easy to derive too. Hint: Euler relation for exp(jφ).