Final answer:
Trigonometric identities can be used to determine the amplitude and phase spectra of different types of functions. Therefore, d) a constant function is correct answer.
Step-by-step explanation:
Trigonometric identities can be used to determine the amplitude and phase spectra of periodic functions, linear functions, exponential functions, and constant functions.
For a periodic function, the amplitude spectrum represents the maximum value of the function, while the phase spectrum represents the angle by which the function is shifted. The amplitude and phase spectra can be determined by analyzing the trigonometric equation representing the function.
For a linear function, the amplitude spectrum is constant and equal to zero, while the phase spectrum is also constant and equal to zero. This is because a linear function does not exhibit any oscillatory behavior.
For an exponential function, the amplitude spectrum represents the magnitude of the exponential growth or decay, while the phase spectrum is constant and equal to zero.
For a constant function, both the amplitude and phase spectra are zero, as there is no variation in the function.