1. Define a periodic function. If f is periodic over an interval [a,b], how can we scale and translate it to be periodic over [-π,π]?
2. What are trigonometric polynomials? What is their period?
3. Define the continuous Fourier series and Fourier transform and explain their importance in terms of frequencies.
4. Explain why a trigonometric basis approximation may not be a good idea if the approximated function f (x) is not periodic.