Disclaimer
These classroom notes are the property of the author(s). You may use them
for reasonable private purposes (that is why they are listed here), but
you should definitely not misuse them. If you do use them, then proper
credit should be given. If you find any errors or have suggestions to
make, then the authors would undoubtedly appreciate your contacting them.
If you have classroom notes on approximation theory or some subset
thereof, in an appropriate format, and are willing to have other people
look at and perhaps make use of these notes (within reason), then we
invite you to contact us so that we can make the necessary links.