S4E26. 无孔不入：数学中的“稠密” - 大老李聊数学（全集）

<p style="color:#333333;font-weight:normal;font-size:16px;line-height:30px;font-family:Helvetica,Arial,sans-serif;hyphens:auto;text-align:justify;" data-flag="normal">度量空间中的“稠密”定义：</p><p style="color:#333333;font-weight:normal;font-size:16px;line-height:30px;font-family:Helvetica,Arial,sans-serif;hyphens:auto;text-align:justify;" data-flag="normal"><img data-key="0" src="http://imagev2.xmcdn.com/storages/063d-audiofreehighqps/4B/BB/GMCoOR8I5Qi_AADLlAJfq1N5.png!op_type=4&device_type=ios&upload_type=attachment&name=mobile_large" alt="" data-origin="http://imagev2.xmcdn.com/storages/063d-audiofreehighqps/4B/BB/GMCoOR8I5Qi_AADLlAJfq1N5.png?op_type=0" data-large="http://imagev2.xmcdn.com/storages/063d-audiofreehighqps/4B/BB/GMCoOR8I5Qi_AADLlAJfq1N5.png!op_type=4&device_type=ios&upload_type=attachment&name=mobile_large" data-large-width="750" data-large-height="163.84915474642392" data-preview="http://imagev2.xmcdn.com/storages/063d-audiofreehighqps/4B/BB/GMCoOR8I5Qi_...