Since the textbooks will be used at a school in New York state, you can apply to the New York State Department of Taxation and Finance for a refund of the sales tax that Amazon collected from you. Use form AU-11:
https://www.tax.ny.gov/pdf/current_forms/st/au11_fill_in.pdf
Refer to New York State Department of Taxation and Finance Tax Bulletin 125 (TB-ST-125):
https://www.tax.ny.gov/pubs_and_bulls/tg_bulletins/st/college_textbooks.htm