如图，在平面直角坐标系中，函数y= $\frac{k}{x}$ （x＞0，k是常数）的图象经过A（2，6），B（m，n），其中m＞2．过点A作x轴垂线，垂足为C，过点B作y轴垂线，垂足为D，AC与BD交于点E，连结AD，DC，CB．

阅读下面一首古诗，完成小题。
                                                                                                                                          雁门太守行
                                                                                                                                               李贺
                                                                                                                      黑云压城城欲摧，甲光向日金鳞开。
                                                                                                                      角声满天秋色里，塞上燕脂凝夜紫。
                                                                                                                      半卷红旗临易水，霜重鼓寒声不起。
                                                                                                                      报君黄金台上意，提携玉龙为君死。

马克思主义诞生的根本原因是