rageskywalker
2022-07-07T08:58:47+00:00
我知道这个题可以提个x出来凑到后面成为x的平方做但是我这个题用三角代换做的，结果跟答案不一样，不知道哪一步错了，求求大神帮我看看，
[img]https://img.nga.178.com/attachments/mon_202207/09/-7Q2q-hwgqXbZ2yT3cSqo-zk.jpg.medium.jpg[/img]
[img]https://img.nga.178.com/attachments/mon_202207/09/-7Q2q-gq4hZ1xT3cSqo-zk.jpg.medium.jpg[/img]
[img]https://img.nga.178.com/attachments/mon_202207/09/-7Q2q-hwgqXbZ2yT3cSqo-zk.jpg.medium.jpg[/img]
[img]https://img.nga.178.com/attachments/mon_202207/09/-7Q2q-gq4hZ1xT3cSqo-zk.jpg.medium.jpg[/img]