Don't say that junior high school is high school. The real foundation is just those things on the whole, one is function and the other is geometry.

Of course, the wider the knowledge coverage, the greater the difficulty, but no matter how to change geometry, how to change geometry, it is impossible to become a series or a derivative vector.

As far as junior high school is concerned, there are several types of functions, namely proportional and anti-linear functions. The geometry of quadratic function is a circle, and the highlight is of course the comprehensive application of analytic geometric circle and similarity. What line segments are proportional, Pythagorean theorem, trigonometric function similarity, congruence, central angle, circumferential angle, of course, the finale of quadratic function is indispensable.

90 points should be enough to understand functions and geometry.