The handwritten version of the handwritten answers to the selected materials for the junior high school mathematics high school exam is here.
This is a recent selection of some of the must-have questions in the high school entrance examination, the most valuable questions in the quadrilateral.
The most valuable question has always been the focus and difficulty of the high school entrance examination, and it is often placed in the position of choosing the fill-in-the-blank finale question. And the last question of the comprehensive finale question is also often encountered.
The mathematics middle school exam is a must to fill in the finale.
Today I would like to share with you the optional finale of the 20 quadrilaterals, mainly involving the maximum and minimum values, each of which is carefully selected, let's take a look at these questions first.
Optional finale one.
Optional finale 2.
In fact, I suggest that students do at least 2~3 optional finale questions every day, and students with a good foundation must persevere, and each optional finale question can accumulate a lot of thinking methods and skills.
Optional Finale Question 3.
Optional Finale Question 4
In addition to the regular generals drinking horses, Hu Bugui, Ah Shi Yuan, Fermat Point and One Arrow Piercing the Heart, there are actually many other weapons involved.
Quadrilateral optional finale 5
Here's a detailed breakdown of the handwritten answers, which basically cover most of the quadrilateral maximums.
Refer to Answer 1.
Question 1 I think is very important, a certain length of the moving line segment, must first determine the trajectory of the moving point, if the trajectory is determined to be linear, then find two special points such as the starting point and the end point to determine the straight line.
Refer to Answer 2.
Question 5 is the translational general drinking horses, and I have already posted a special video. Question 6 can be classified as an inverse isochal model, or it can be done in a conventional way.
Refer to Answer 3.
Question 12 is the conventional hidden circle model, which is still very important.
Refer to Answer 4
Question 14 skillfully uses the median line transformation, and then uses the relationship between the three sides of the triangle to find the maximum, Question 15 also uses the relationship between the three sides, and Question 16 is a very good hidden circle model and a arrow through the heart problem.
Refer to Answer 5.
Problem 18 is also an inverse isolinear model, but this problem can be converted with a parallelogram. Question 19 is the slide model, which is the simplest of the most valuable models. Question 20 uses the conventional method of setting parameters, using a quadratic function to find the maximum. In fact, there are many ways, and the most convenient method is to choose the most convenient one.