The normal order is set, logical language, definition properties of function and some basic functions. The sequence is mainly the application of arithmetic progression, geometric progression, trigonometric function, sine theorem, cosine theorem, inequality (this is optional in some places), especially the mean inequality, straight line and circle, conic curve (parabola, hyperbola, ellipse), solid geometry (three views are very simple, straight lines are in different planes, this one should have a sense of space), and probability problems. Expect (on average) to know how to find, geometric distribution and binomial distribution), derivative (this high school stage is relatively simple, so long as you remember the formula, you can apply it), complex number (this high school has less content and is easy to learn), and some places need to learn polar coordinates (optional). That's about all the knowledge in high school. Not difficult.