Special post mathematics is not difficult, it is a basic problem. As long as you work hard, do well the college entrance examination questions and the special post questions, and then go through the knowledge system, there will be no problem. 1, understand set and representation, and master the definitions of subset, complete set and complement set, subset and union set; 2. Master the solution of inequality with absolute value and quadratic inequality with one variable; 3. To understand the meaning of logical conjunctions, we can skillfully transform four propositions and master the reduction to absurdity; 4. Understanding the meaning of sufficient condition, necessary condition and necessary and sufficient condition will judge the necessary and sufficient relationship between the two propositions; 5. Learn to solve problems with definitions, understand the combination of numbers and shapes, discuss them in categories, and transform them into equivalents.