SIKFEE 2020-10-17T08:05:56+00:00 [img]https://img.nga.178.com/attachments/mon_202010/23/-7Q5-fbdKlT3cSmk-kc.png[/img]a为粉色正方形边长,S为粉色正方形的内接正方形面积,求∠A与S的函数关系式