20 14 Anhui college entrance examination is difficult in mathematics, which is a diversified investigation of candidates. Investigate the same knowledge point from multiple angles, and investigate the properties and applications of functions by combining different carriers in different ways. Examining the same knowledge point from multiple angles, combining with different carriers, and examining the nature and application of functions through different channels (a small question examines multiple core knowledge points, and reasonably connects and integrates knowledge points such as permutation and combination, vector, product of quantity, maximum value and inequality, so as to effectively tap the mathematical potential of examination.