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Basic trig phase question *sorry* 
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#1
May1112, 01:02 AM

P: 10

I'm a bit rusty..
I have a cosine y = cos(2*pi*f*t) If I want to advance the cosine by say 90 degrees y = cos(2*pi*f*t + pi/2) but.. this waveform has f cycles per 2*pi*t..so won't I be advancing the phase by f*pi/2? someone pls straigthen me out  I'm working with Matlab indexes and I'm getting confused! 


#2
May1112, 04:08 AM

P: 606

I'm not really sure what're you asking, but [itex]\,\,\displaystyle{\cos \left(\alpha+\frac{\pi}{2}\right)=\sin (\alpha)}\,\,[/itex] DonAntonio 


#3
May1112, 08:07 AM

Math
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Thanks
PF Gold
P: 39,682

cos(2*piZ*f*t+ pi/2) is different from cos(2*pi*f(t+ pi/2)). The first just translates the wave by pi/2, the second translates by pi^2*f.



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