But I usually think the same as you, and I also went to find some information to study. What I know is very useful to me is the following:
① Hardware decoding theorem of conic curve, memorizing four formulas, 80% of conic curve problems should be no problem. Practical 5 stars
(2) Fixed-point solution to the order problem, such problems are generally put on the finale, and the probability of occurrence is extremely small. In the college entrance examination for several years, it has hardly appeared, but once it appears, it will pull the gap. Practical 1 star
(3) Robida's law, for some questions that can't get the maximum value of the function, but whether the penalty is unknown, you can get the answer quickly, and the answer is definitely correct. Practical 3 stars
(4) Polar coordinates, for the conic focus chord problem, polar coordinates can be regarded as a second kill. Practical 4 stars
⑤ Finding the extreme value of multivariate function involves some concepts such as partial derivative, but this leads to something called "symmetry method".
For example, x+y= 1, find the maximum value of xy. Both X and Y have changed, and the topic conditions remain unchanged, so it is practical to take the maximum value of 3 stars when X = Y.
⑥ Other things, such as Lagrange mean value theorem, concave-convex function, derivative of implicit function, polar line of conic curve, affine and transformation, are not recommended. . .
A hint, don't pay too much attention to the methods outside the classroom, otherwise it is likely to limit your thinking. If you want to use other methods when you see the problem, you may get twice the result with half the effort. You'd better know when to use it, which will help you improve your grades.
I hope it will be adopted. I wish you a happy study.