笔者在思考第26届“希望杯”高一年级1试第19题时,发现该题与课本中的一道习题如出一辙,在平时教学过程中也时常遇到此类问题,很有价值,于是和同事作了较为深入的探究.赛题在平面直角坐标系中,过点P(m,n)(m≠0,n≠0)的直线l与两坐标轴围成的三角形的面积是定值M,则这样的直线可能有 When I was thinking about the 26th “Hope Cup” high school grade 1 test, I found that this question was exactly the same as a textbook. In the usual teaching process, I often encounter such problems, which is very valuable. Therefore, I made a deeper exploration with my colleagues.It is found that the area of ​​the triangle surrounded by the straight line l and the two coordinate axes P (m, n) (m ≠ 0, n ≠ 0) in the Cartesian coordinate system is The fixed value M, then such a straight line may have