例题已知两条异面直线所成的角为θ,如图1,在直线a,b上分别取E,F,已知A′E=m,AF=e,EF=l,求公垂线段AA′的长d.(人教版新教材第二册下(B)P49例2)研究1思路的探求课本是用向量加法求解,体现向量在解题中的重要性,但学生普遍难于接受.笔者讲授这道题时,不是直接“抛”出该题,考虑 For example, we know that the angle formed by two different surfaces is θ, as shown in Figure 1, E and F are respectively taken on the straight lines a and b, known as A’E = m, AF = e and EF = l The length of line AA ’d. (People’s Education Press, New Teaching Materials Volume II (B) P49 cases 2) to explore a train of thought textbook solution is to use vector addition, reflecting the importance of vector in the problem-solving, but students generally difficult Accept the author when I teach this topic, not directly “throw” the problem, consider