Yeah. I've just been doing precalc for the last 75 hours.
我这75个小时都在补微积分学前课。
英语百科
Precalculus
（重定向自Precalc）
In mathematics education, precalculus is a course with college-level algebra and trigonometry that is designed to prepare students for the study of calculus. Schools often distinguish between algebra and trigonometry as two separate parts of the coursework.