Tips to Remember
1. All sinusoids being represented by complex numbers must have the same frequency in order to combine the sinusoids by simply adding or subtracting the complex numbers themselves. 2. When representing sinusoids through the use of complex numbers, signals can be added or subtracted, provided their frequencies are the same, to produce a new signal. This is not true, however, for the case of multiplication. If you take the product of two complex numbers representing two sinusoidal signals, the result of this multiplication will not be the same as the product of the two sinusoids.
