
1) Apple II peripheral 2) Electrical circuit 3) Radio electronic 
Found on 
https://www.crosswordclues.com/clue/phasor

 Another way to view addition is that two vectors with coordinates [A1 cos(ωt + θ1), A1 sin(ωt + θ1)] and [A2 cos(ωt + θ2), A2 sin(ωt + θ2)] are added vectorially to produce a resultant vector with coordinates [A3 cos(ωt + θ3), A3 sin(ωt + θ3)]. (see animation) === Phasor diagrams === Electrical engineers, electronics engineers, electro...
Found on 
http://en.wikipedia.org/wiki/Phasor
 [sound synthesizer]
[sound synthesizer]  Phasor is a stereo music, sound and speech synthesizer created by Applied Engineering for the Apple II family of computers. Consisting of a sound card and a set of related software, the Phasor system was designed to be compatible with most software written for other contemporary Apple II cards, including the Mockingboard...
Found on 
http://en.wikipedia.org/wiki/Phasor_(sound_synthesizer)

representation of a sinusoidal quantity by a complex quantity whose argument is equal to the initial phase and whose modulus is equal to the root-mean-square value or to the amplitude NOTE 1 - For a quantity a(t) = A v2 cos (? t + ?
0) = A
m cos (? t + ?
0) the phasor is ei...
Found on 
http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=101-14-62

representation of a sinusoidal integral quantity by a complex quantity whose argument is equal to the initial phase and whose modulus is equal to the root-mean-square value NOTE 1 - For a quantity a(t) = A v2 cos(?t +?
0) the phasor is A exp j?
0 . NOTE 2 - The similar representation with the mo...
Found on 
http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=131-11-26
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