# Homework Help: AC Circuits values problem

1. Aug 7, 2011

### joe007

1. The problem statement, all variables and given/known data

A complex AC voltage is given by the equation
v = 3e^j450t :
Note the use of bold v to represent the complex voltage.
For this voltage waveform, what are the values of
-volltage amplitide
-frequency
-instantaneous voltage
-graph it in a argand diagram at t=pi/1800

2. Relevant equations

V=Vocoswt

w=2PIf

3. The attempt at a solution
-well so far i know the voltage amplitude is 3 volts
-j is an imaginary number
-the expansion is v=3(cos450t+jsin450t)

Last edited by a moderator: May 21, 2018
2. Aug 7, 2011

### rock.freak667

I think you mean V = 3(cos450t+jsin450t)

Which is comparable to the form V= V0(cosωt+jsinωt) where ω is the angular frequency.

For the instantaneous voltage, are they asking it for the time at t = π/1800 ?

3. Aug 8, 2011

### joe007

dats right, so the frequency is 450/2pi

4. Aug 8, 2011

### joe007

but how can i draw the argand diagram?

5. Aug 8, 2011

### rock.freak667

Well in V = 3(cos450t+jsin450t)
just put t= π/1800 and you will get a complex number in the form V = a+jb to draw which should be easy for you to do.