Final answer:
The output of an LTI system when a 100Hz sine wave is introduced will also be a 100Hz sine wave, but the amplitude and phase could change depending on the system's response.
Step-by-step explanation:
When you introduce a sine wave with a frequency of 100Hz to a Linear Time Invariant (LTI) system, the output of the system will be a sine wave at the same frequency, 100Hz, given that the system is ideal and there is no frequency-dependent behavior, such as filtering. However, the amplitude and phase of the output wave may change based on the system's frequency response characteristics.
If the LTI system has a flat frequency response over the range of the input, the amplitude of the output will be proportional to the input, and the phase shift will be constant. If the system behaves as a filter, then the output amplitude may be attenuated or amplified, and the phase shift could vary depending on whether the filter is low-pass, high-pass, band-pass, or band-stop.