As a rule, the library does not purchase textbooks for the collection, due to the high cost of text books, along with frequent changes and updates. The cost of maintaining and updating such a textbook collection would not be sustainable.
On occasion we may, however, end up having a book in the collection that just happens to the one your professor is using as a textbook. You can check this using the One-Search Library Catalog (the big search box in the middle of the library home page).
Finally, you can check to see if your instructor has placed the textbook on course reserve. This means we are holding the textbook at the library, and it will be available to check out for short periods (usually a couple of hours). You can find out using the course reservesearch.