In other words, after finishing junior high school in China, you can go directly to the calculus preparatory course.
Mainly involves the knowledge of some functions (especially trigonometric functions). After taking the pre-calculus course, you have theoretically completed the mathematics in American high schools.
American high schools don't stipulate which math concepts should be taught in which grade.
Instead, students are required to choose the math course that suits them best according to the tests and tests.
Therefore, there are differences in teaching systems between schools and between states.