Which is the simplest, geometry, inequality and coordinate system?
This is based on your mastery of knowledge points. Many solid geometry and coordinate system are the same, and many solid geometry solutions will establish coordinate system. Generally, the steps to solve the formula are definite, but it is actually very simple to remember. Inequality may be simple, that is, it is discussed by adding letters, but it is easy to miss, depending on whether you think comprehensively or not.