- #1
CricK0es
- 54
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Homework Statement
a.) Find the resultant of the two waves: Phasor method
[tex] E1 = 4cos(ωt) [/tex] & [tex] E2 = 3cos(ωt+\frac{\pi}{2}) [/tex]
b.) By algebraically writing
[tex] E1 = 4cos(ωt+α-α) [/tex] & [tex] E2 = 3cos(ωt+α+\frac{\pi}{2}-α) [/tex]
Choose α to make the wave have only a cosine term
Homework Equations
The Attempt at a Solution
I'll show my working for the algebraic attempt so far, then try and see how to do it via phasors later.
[tex] E0 = E1 + E2 [/tex]
[tex] E0 = 4cos(ωt+α-α)+3cos(ωt+α+\frac{\pi}{2}-α) [/tex]
My ability to use LaTeX ran out... sorry, I just couldn't get it to work. I'll try to keep it clear... ;(
[ 4 . Cos(α) + 3 . Cos( π/2 - α) ] . Cos(ωt + α) + [ 4 . Sin(α) - 3 . Sin( π/2 - α) ] . Sin(ωt + α)
Make the wave have only a cosine term ∴
[ 4 . Sin(α) - 3 . Sin( π/2 - α) ] = 0
4. Sin(α) = 3. Cos(α)
tan(α) = 3/4
That's pretty much as far as I got. I wasn't sure what to do after this. Any help would me much appreciated.
Many thanks...
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