When to ignore air resistance

This paper talks about how most introductory physics textbooks are awful and provide unrealistic approximations, with no comments on their applicability.

The observant student knows—from exploring the world—that golf drives rise quickly and almost straight and drop parabolically only near the end. This student learns that the world described by her physics textbook is not the real world and that careful observation is irrelevant to physics.

Contrast the experience of the curious student with that of a student who parrots equations and regurgitates textbook paragraphs. This student is untroubled by the golf problem or its variants listed in Table I because he knows the easily memorized “fact” that all trajectories are parabolae. […]

If you ever took a physics class, I’m quite sure you recognize that teaching style. The following figure shows the trajectory of a golf ball considering air resistance, in case you’re interested: