[jerf]

And you may be falling into the trap that because it's useful to you, it's useful to lots of people. Again, it's not about "is it valuable", it's about opportunity costs! While you're fiddling with trig you're not learning other more useful things.

Let it be learned when it's actually useful. If you use it in physics, fine, learn it there, when you have context. Not in some abstracted "trig" course.

To be honest, I'm not sure I believe you anyhow. I took a lot of physics, as much as anyone not majoring in it will take, and I did not make heavy use of trig identities, nor did anybody else, nor do I recall a huge number of problems where they would have come in useful, and what problems they might have been useful in were textbook problems anyhow. (In the real world, inclined planes are not all at 30 and 45 degrees.) I think you might just be saying that to score rhetorical points.

[scott_s]

But what are the more useful things? That depends heavily on what, exactly, you go into. For many people, most of the math they took is never used. But that's not known at the high school level, so a high school education tries to serve as a foundation for further learning. You're assuming discrete math would be more useful to more students than trig. I doubt this is true.

If I had to learn trig my freshmen and sophomore year of college, when I was taking my introductory physics classes, I never would have kept up with the physics. My course assumed a solid foundation in trig and calculus.

I distinctly remember having to use various properties of triangles to solve many of my introductory mechanics problems.