[bluGill]

Trig is generally called per-calculus in US high schools. It is not a required course, but it is one of the courses everyone on the college track is expected to take.

Though most people haven't used any of that since college and so don't know it very well anymore. I smelled BS when I read the blog, but couldn't put my finger on why - the comment you replied to explained what I knew was the case but couldn't remember.

[happimess]

    s/per-calculus/pre-calculus/g

[kortex]

The percalculus ion is just calculus in its highest oxidation state.