关键字:求斜率之比为定值,夹角最大,极点极线的调和性,背景,抛物线的平均性质 https://m.toutiao.com/article/7108673464168595972/?app=news_article×tamp=1659476084&use_new_style=1&req_id=202208030534430101320652 080A309A60&group_id=7108673464168595972&wxshare_count=1&tt_from=weixin&utm_source=weixin&utm_medium=toutiao_android&utm_campaign=client_share&share_token=b4a7101a-c944-4314-9958-f96fce75d742
数学流
数学流
