Compulsory two and compulsory three or compulsory four. Hey, homework help. Com, as of July, 2023 12, Senior Two Mathematics in Daxing District, Beijing: compulsory 2 (initial analytic geometry and solid geometry), elective 2- 1 (conic curve), elective 2-2 (classification and numbering principle) and elective 2-3 (permutation and combination).