Unit 3. Jiangsu, referred to as "Su" for short, is the provincial administrative region of People's Republic of China (PRC). The third unit of elective compulsory mathematics is conic curve, mainly ellipse, hyperbola and parabola. Knowledge points are complex and difficult to understand, which is more difficult than the space vector problem in Unit 1. Students are required to have a deep understanding of the equation of the curve, so as to understand the formation mode of the curve.