Elective Course 4-5 (Special Lecture on Inequality). Senior high school mathematics (liberal arts): required parts: compulsory 1, compulsory 2, compulsory 3, compulsory 4, compulsory 5, elective 1- 1-2. Elective courses: Elective courses 4- 1 (Selected lectures on geometry proof), Elective courses 4-2 (Matrix and Transformation), Elective courses 4-4 (Coordinate System and Parameter Equation), Elective courses 4-5 (Selected lectures on inequality). Judging from the difficulty coefficient, the elective course 4-5 (inequality elective course) is not studied. The liberal arts comprehensive ability test, referred to as "liberal arts comprehensive" or "literature comprehensive", refers to the examination paper composed of politics, history and geography in the college entrance examination, that is, "3" in the "3+X" test refers to Chinese, mathematics (divided into liberal arts mathematics and science mathematics) and English, and "X" refers to literature comprehensive composed of politics, history and geography. The score is twice that of Chinese, mathematics and English (300 points for literature or science, 0/50 points for Chinese, mathematics and English). Candidates choose whether to study liberal arts or science. If the chosen liberal arts is a literary synthesis composed of politics, history and geography, then "synthesis" is "liberal arts synthesis".