MATH 322 Harmonic Analysis
Homework # 7
Due Friday, March 23.
- Read Chapter 5, Section 1. Read Exercises #1--10. Do Exercises
#1, 2, and 4 -- 10. Hand in #2, 6, 8, and 9.
Write up your results carefully.
Here are some comments on the exercises.
- Exercise 1. This is a nice exercise which brings together the
theories of Fourier series and Fourier transform.
- Exercise 2. I did part of this in class. Comparison of f and g
illustrates that greater smoothness is transformed into faster decay.
- Exercise 3. More about smoothness and decay.
- Exercise 4. I did this in class.
- Exercise 5. I did some of this in class. For (b), think about
using the Riemann-Lebesque Lemma.
- Exercise 6. The functions you are asked to find are the
eigenfunctions of the Fourier transform. As a hint, try
multiplying the Gaussian by a polynomial. Look at Problem #7. (That's
NOT Exercise #7.)
- Exercise 7. I did a similar computation in class.
- Exercise 8. The hint should be enough to get you started, but
there is more to be done.
- Exercise 9. A direct analog to Fejer's Theorem for Fourier
series.
- Exercise10. I guess this will be your third proof of the
Weierstrass Theorem.