Recite the theorem on the circle again, and you can use it when you study.
Vieta theorem, when learning a function, the symmetry axis on the quadratic function δ should be combined with the image.
There are still many, I can't remember.
Helen's formula, bernhard's inequality, Cauchy's inequality, these are not only in junior high school, but teachers may not speak them. The college entrance examination can be used sometimes, so it's best to know them.
What I said may not be used at ordinary times, and I may not notice it when I study related chapters. It's for the college entrance examination.