It must be an improper study method. To learn mathematics, we must first read the textbook carefully, thoroughly understand every concept in the textbook, master theorem proving, remember theorem conclusion, and skillfully recite basic knowledge such as formulas, properties, images, etc., so as to achieve an unforgettable degree. Then master the basic problem-solving methods by doing problems, improve the basic skills and further consolidate the basic knowledge. In short, we should consolidate three foundations: basic knowledge, basic methods and basic skills. You should know: the foundation is not firm, the earth shakes, and the basic knowledge is the magic weapon to change with constancy! Practice makes perfect, and success comes naturally.