It appears that your daughter is your dependent, assuming she’s listed as such on your return. But whether you qualify to take the American opportunity credit or the lifetime learning credit depends on how long she’s been in college and the amount of your modified adjusted gross income; check the instructions for Form 8863.
A revenue ruling is the Commissioner’s “official interpretation of the interpretation of the law” and generally is binding on revenue agents and other IRS officials. Taxpayers generally may rely on published revenue rulings in determining the tax treatment of their own transactions that arise out of similar facts and circumstances.