在人教版高中数学新教材第二册(下B)中介绍了空间向量的共线定理:对空间任意两个向量a,b(b≠0),a与b共线的充要条件是存在唯一实数λ,使得a=λb.由这个共线定理,我们可以推导出它的一个推论:设OA,OB是平面内不共线的两个向量,则点A,B,P三点共线的充要条件是存在唯一的一对实数x,y,使得OP=xOA+yOB(x+y=1).在近几年的高考备考中,发现有不少的题目,如果能够充分用好这个共线定理的推 The co-linear theorem of space vector is introduced in the second edition of the PEP textbook (under B). The necessary and sufficient conditions for collinearity of a and b for any two vectors a and b (b ≠ 0) There is a unique real number λ such that a = λb. From this collinear theorem, we can deduce one of its inferences: Let OA, OB be two vectors that are not collinear in the plane, then point A, B, P The necessary and sufficient conditions for the existence of the line is the existence of a unique pair of real numbers x, y, making OP = xOA + yOB (x + y = 1). In recent years, entrance examination pro forma, there are many problems found, This is a good push of the collinear theorem