释义 |
Harmonic Addition TheoremTo convert an equation of the form
 | (1) |
to the form
 | (2) |
expand (2) using the trigonometric addition formulas to obtain
 | (3) |
Now equate the Coefficients of (1) and (3)
so
 | (6) |
 | (7) |
and we have
Given two general sinusoidal functions with frequency :
their sum can be expressed as a sinusoidal function with frequency 
Now, define
 | (13) |
 | (14) |
Then (12) becomes
 | (15) |
Square and add (13) and (14)
 | (16) |
Also, divide (14) by (13)
 | (17) |
so
 | (18) |
where and are defined by (16) and (17).
This procedure can be generalized to a sum of harmonic waves, giving
 | (19) |
where
and
 | (22) |
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