- 세상의 모든 계산기 자유(질문) 게시판 일반 ()
클라우드 서버 sshd 포트 열어뒀더니... 많이 들어오는군요.

지금의 세모계 서버를 열어둔 건 아니고,
다른 서버 테스트용으로 하나 만들어서 열어만 둔 거 있는데
어떻게 알고 또 귀신같이 들러붙네요.
fail2ban 돌려봤더니 이틀만에 ban list에 149개 등록
Status for the jail: sshd
|- Filter
| |- Currently failed: 11
| |- Total failed: 463
| `- Journal matches: _SYSTEMD_UNIT=sshd.service + _COMM=sshd
`- Actions
|- Currently banned: 149
|- Total banned: 149
`- Banned IP list: 60.199.224.55 43.134.121.65 103.248.60.70 41.111.234.136 34.66.72.251 24.199.113.111 14.6.81.179 159.89.168.110 5.250.188.211 103.26.136.173 14.225.213.232 45.89.233.214 128.199.150.58 60.199.224.2 202.157.176.210 151.80.61.151 161.35.121.67 167.86.81.130 69.49.246.187 95.167.225.76 43.134.185.197 51.222.106.104 138.68.161.220 118.194.230.250 190.129.60.125 149.129.67.202 138.84.41.218 115.160.146.86 162.241.126.244 72.167.44.240 57.128.172.114 159.89.154.119 201.48.76.244 43.134.103.193 103.143.72.165 104.248.36.106 125.20.16.22 43.135.129.247 52.233.80.34 114.34.106.146 118.70.48.219 154.92.16.94 136.232.203.134 14.63.221.137 159.65.161.118 136.232.98.230 141.94.246.192 179.33.186.151 177.85.247.230 143.198.145.136 103.98.4.35 128.199.214.193 161.35.231.77 24.199.103.14 122.155.0.205 183.110.116.65 181.188.159.138 64.23.206.49 106.51.1.72 186.121.205.29 61.222.211.114 43.224.48.86 128.199.73.168 87.201.127.149 49.51.228.223 89.183.192.60 95.90.242.212 82.142.13.233 129.226.212.125 181.212.81.228 51.79.27.107 213.225.14.135 154.72.194.207 45.238.232.3 182.57.16.58 27.112.78.50 73.135.38.134 74.249.18.64 210.17.230.213 103.94.113.2 45.156.23.56 103.69.220.19 213.215.140.6 45.175.157.53 34.139.17.74 190.181.15.3 195.133.2.209 41.138.54.13 101.47.5.97 64.227.174.243 190.111.252.40 206.189.22.29 103.187.147.32 185.6.9.159 78.187.21.105 181.174.224.99 65.49.196.227 61.84.35.21 212.49.70.200 36.92.214.178 123.30.98.134 51.79.144.105 104.168.22.62 123.58.214.42 178.128.84.59 27.71.25.96 123.58.214.129 43.157.183.148 103.187.146.162 128.199.5.115 105.174.43.194 201.249.204.178 118.91.162.78 180.225.174.116 138.197.168.82 143.198.209.18 103.90.67.83 147.45.77.165 27.254.192.185 203.12.203.114 34.142.110.144 206.189.45.206 2.189.175.19 37.58.18.216 186.124.22.55 157.245.151.195 45.119.81.249 103.130.215.82 59.103.120.51 69.49.247.85 134.122.8.241 51.68.126.207 103.199.145.82 178.62.194.205 178.32.172.153 139.255.87.220 213.149.166.200 103.53.28.93 103.154.123.19 104.250.56.198 165.227.118.246 95.174.102.56 185.141.132.26 103.84.236.242 134.209.162.179 104.168.30.102 142.44.162.161 134.209.181.159 121.141.64.213
역시 sshd 포트는 특정 IP만 접근할 수 있게 막아두는게 최선인 듯 합니다.
댓글6
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세상의모든계산기
집에 공유기 방화벽 기록을 봤더니... 여기도 장난 아니네요.
10/12/2024 10:08:03 Ping Of Death from 183.61.109.222 to 공유기 droped
10/12/2024 10:09:43 Ping Of Death from 74.3.163.37 to 공유기 droped
10/12/2024 10:57:08 Ping Of Death from 132.145.22.18 to 공유기 droped
10/12/2024 10:59:48 Ping Of Death from 43.128.69.194 to 공유기 droped
10/12/2024 11:29:57 Ping Of Death from 58.144.142.140 to 공유기 droped
10/12/2024 11:33:46 Ping Of Death from 43.130.90.69 to 공유기 droped
10/12/2024 11:44:17 Ping Of Death from 35.172.109.225 to 공유기 droped
10/12/2024 12:17:51 Ping Of Death from 50.116.23.150 to 공유기 droped
10/12/2024 12:25:30 Ping Of Death from 101.66.161.106 to 공유기 droped
10/12/2024 12:27:32 Ping Of Death from 170.39.225.162 to 공유기 droped
10/12/2024 13:02:06 Ping Of Death from 52.81.237.148 to 공유기 droped
10/12/2024 13:40:30 Ping Of Death from 194.195.122.95 to 공유기 droped
10/12/2024 14:02:32 Ping Of Death from 54.225.49.201 to 공유기 droped
10/12/2024 14:23:30 Ping Of Death from 76.8.60.71 to 공유기 droped
10/12/2024 14:32:22 Ping Of Death from 71.136.112.66 to 공유기 droped
10/12/2024 14:35:32 Ping Of Death from 162.62.58.193 to 공유기 droped
10/12/2024 14:51:52 Ping Of Death from 119.147.86.35 to 공유기 droped
10/12/2024 15:54:58 Ping Of Death from 43.156.12.125 to 공유기 droped
10/12/2024 16:00:30 Ping Of Death from 60.188.112.159 to 공유기 droped
10/12/2024 16:09:13 Ping Of Death from 52.81.253.27 to 공유기 droped
10/12/2024 16:12:17 Ping Of Death from 113.200.63.216 to 공유기 droped
10/12/2024 16:34:37 Ping Of Death from 163.47.21.77 to 공유기 droped
10/12/2024 17:10:21 Ping Of Death from 61.240.29.164 to 공유기 droped
10/12/2024 17:13:34 Ping Of Death from 172.104.45.135 to 공유기 droped
10/12/2024 17:31:04 Ping Of Death from 101.71.134.164 to 공유기 droped
10/12/2024 18:06:27 Ping Of Death from 38.180.77.40 to 공유기 droped
10/12/2024 18:46:54 Ping Of Death from 43.128.69.194 to 공유기 droped
10/12/2024 19:08:21 Ping Of Death from 107.20.15.252 to 공유기 droped
10/12/2024 19:24:12 Ping Of Death from 54.88.147.30 to 공유기 droped
10/12/2024 19:39:58 Ping Of Death from 35.213.11.235 to 공유기 droped
10/12/2024 19:40:37 Ping Of Death from 170.39.225.147 to 공유기 droped
10/12/2024 19:50:27 Ping Of Death from 52.80.238.175 to 공유기 droped
10/12/2024 19:52:55 Ping Of Death from 113.57.9.146 to 공유기 droped
10/12/2024 20:02:46 Ping Of Death from 223.15.244.251 to 공유기 droped
10/12/2024 20:48:15 Ping Of Death from 185.157.232.103 to 공유기 droped
10/12/2024 20:51:33 Ping Of Death from 123.184.59.71 to 공유기 droped
10/12/2024 21:02:43 Ping Of Death from 49.72.213.128 to 공유기 droped
10/12/2024 21:17:21 Ping Of Death from 204.216.214.162 to 공유기 droped
10/12/2024 21:26:21 Ping Of Death from 112.95.75.94 to 공유기 droped
10/12/2024 21:32:22 Ping Of Death from 54.225.49.201 to 공유기 droped
10/12/2024 21:55:41 Ping Of Death from 125.76.82.92 to 공유기 droped
10/12/2024 21:56:09 Ping Of Death from 52.81.237.148 to 공유기 droped
10/12/2024 21:59:36 Ping Of Death from 39.175.5.126 to 공유기 droped
10/12/2024 22:04:45 Ping Of Death from 162.62.58.193 to 공유기 droped
10/12/2024 22:06:44 Ping Of Death from 129.151.234.14 to 공유기 droped
10/12/2024 22:06:57 Ping Of Death from 170.106.14.53 to 공유기 droped
10/12/2024 22:16:29 Syn flood From IP 78.135.100.167 port 2829 to IP 공유기 port 22 droped
10/12/2024 22:16:29 Null Scan from IP 78.135.100.167 port 2829 to IP 공유기 port 22 droped
10/12/2024 22:16:36 Syn flood From IP 188.132.189.27 port 16993 to IP 공유기 port 22 droped
10/12/2024 22:16:36 Null Scan from IP 188.132.189.27 port 16993 to IP 공유기 port 22 droped
10/12/2024 22:16:42 Syn flood From IP 185.73.202.178 port 7037 to IP 공유기 port 22 droped
10/12/2024 22:16:42 Null Scan from IP 185.73.202.178 port 7037 to IP 공유기 port 22 droped
10/12/2024 22:16:47 Syn flood From IP 188.132.191.15 port 13855 to IP 공유기 port 22 droped
10/12/2024 22:16:47 Null Scan from IP 188.132.191.15 port 13855 to IP 공유기 port 22 droped
10/12/2024 22:16:51 Syn flood From IP 212.64.201.144 port 5479 to IP 공유기 port 22 droped
10/12/2024 22:16:51 Null Scan from IP 212.64.201.144 port 5479 to IP 공유기 port 22 droped
10/12/2024 22:16:53 Syn flood From IP 188.132.236.53 port 31509 to IP 공유기 port 22 droped
10/12/2024 22:16:53 Null Scan from IP 188.132.236.53 port 31509 to IP 공유기 port 22 droped
10/12/2024 22:16:53 Syn flood From IP 185.73.201.250 port 12893 to IP 공유기 port 22 droped
10/12/2024 22:16:53 Null Scan from IP 185.73.201.250 port 12893 to IP 공유기 port 22 droped
10/12/2024 22:16:54 Syn flood From IP 185.73.200.91 port 10059 to IP 공유기 port 22 droped
10/12/2024 22:16:54 Null Scan from IP 185.73.200.91 port 10059 to IP 공유기 port 22 droped
10/12/2024 22:16:56 Syn flood From IP 212.64.202.222 port 28481 to IP 공유기 port 22 droped
10/12/2024 22:16:56 Null Scan from IP 212.64.202.222 port 28481 to IP 공유기 port 22 droped
10/12/2024 22:17:03 Syn flood From IP 185.165.77.192 port 31945 to IP 공유기 port 22 droped
10/12/2024 22:17:03 Null Scan from IP 185.165.77.192 port 31945 to IP 공유기 port 22 droped
10/12/2024 22:17:10 Syn flood From IP 188.132.249.212 port 28785 to IP 공유기 port 22 droped
10/12/2024 22:17:10 Null Scan from IP 188.132.249.212 port 28785 to IP 공유기 port 22 droped
10/12/2024 22:17:16 Syn flood From IP 212.64.217.193 port 22689 to IP 공유기 port 22 droped
10/12/2024 22:17:16 Null Scan from IP 212.64.217.193 port 22689 to IP 공유기 port 22 droped
10/12/2024 22:17:16 Syn flood From IP 188.132.190.59 port 32187 to IP 공유기 port 22 droped
10/12/2024 22:17:16 Null Scan from IP 188.132.190.59 port 32187 to IP 공유기 port 22 droped
10/12/2024 22:17:22 Syn flood From IP 194.177.14.200 port 17363 to IP 공유기 port 22 droped
10/12/2024 22:17:22 Null Scan from IP 194.177.14.200 port 17363 to IP 공유기 port 22 droped
10/12/2024 22:17:24 Syn flood From IP 185.17.113.195 port 12861 to IP 공유기 port 22 droped
10/12/2024 22:17:24 Null Scan from IP 185.17.113.195 port 12861 to IP 공유기 port 22 droped
10/12/2024 22:17:29 Syn flood From IP 212.68.55.229 port 479 to IP 공유기 port 22 droped
10/12/2024 22:17:29 Null Scan from IP 212.68.55.229 port 479 to IP 공유기 port 22 droped
10/12/2024 22:17:33 Syn flood From IP 212.64.216.143 port 16719 to IP 공유기 port 22 droped
10/12/2024 22:17:33 Null Scan from IP 212.64.216.143 port 16719 to IP 공유기 port 22 droped
10/12/2024 22:17:38 Syn flood From IP 212.68.35.148 port 633 to IP 공유기 port 22 droped
10/12/2024 22:17:38 Null Scan from IP 212.68.35.148 port 633 to IP 공유기 port 22 droped
10/12/2024 22:17:40 Syn flood From IP 212.68.60.16 port 4167 to IP 공유기 port 22 droped
10/12/2024 22:17:40 Null Scan from IP 212.68.60.16 port 4167 to IP 공유기 port 22 droped
10/12/2024 22:17:41 Syn flood From IP 185.17.112.51 port 13305 to IP 공유기 port 22 droped
10/12/2024 22:17:41 Null Scan from IP 185.17.112.51 port 13305 to IP 공유기 port 22 droped
10/12/2024 22:17:45 Syn flood From IP 185.17.114.218 port 27459 to IP 공유기 port 22 droped
10/12/2024 22:17:45 Null Scan from IP 185.17.114.218 port 27459 to IP 공유기 port 22 droped
10/12/2024 22:18:02 Ping Of Death from 71.136.112.66 to 공유기 droped
10/12/2024 22:18:16 Syn flood From IP 212.64.218.160 port 9335 to IP 공유기 port 22 droped
10/12/2024 22:18:16 Null Scan from IP 212.64.218.160 port 9335 to IP 공유기 port 22 droped
10/12/2024 23:12:43 Ping Of Death from 102.213.6.54 to 공유기 droped
10/13/2024 00:15:42 Ping Of Death from 36.250.73.3 to 공유기 droped
10/13/2024 00:19:49 Ping Of Death from 43.156.12.125 to 공유기 droped
10/13/2024 00:24:18 Ping Of Death from 170.80.110.63 to 공유기 droped
10/13/2024 00:24:56 Ping Of Death from 43.157.82.161 to 공유기 droped
10/13/2024 00:31:59 Ping Of Death from 113.57.9.146 to 공유기 droped
10/13/2024 00:34:06 Ping Of Death from 107.155.21.87 to 공유기 droped
10/13/2024 00:55:32 Ping Of Death from 35.172.109.225 to 공유기 droped
10/13/2024 01:25:02 Ping Of Death from 129.226.145.164 to 공유기 droped
10/13/2024 01:26:22 Ping Of Death from 23.133.64.100 to 공유기 droped
10/13/2024 02:00:41 Ping Of Death from 218.98.6.201 to 공유기 droped
10/13/2024 02:01:00 Ping Of Death from 45.116.14.27 to 공유기 droped
10/13/2024 02:03:58 Ping Of Death from 45.131.71.130 to 공유기 droped
10/13/2024 02:20:10 Ping Of Death from 120.246.123.50 to 공유기 droped
10/13/2024 02:25:11 Ping Of Death from 43.128.69.194 to 공유기 droped
10/13/2024 02:56:18 Ping Of Death from 81.70.59.196 to 공유기 droped
10/13/2024 03:06:05 Ping Of Death from 54.88.147.30 to 공유기 droped
10/13/2024 03:22:41 Ping Of Death from 185.94.111.1 to 공유기 droped
10/13/2024 03:46:50 Ping Of Death from 119.188.182.153 to 공유기 droped
10/13/2024 04:03:02 Ping Of Death from 112.81.91.191 to 공유기 droped
10/13/2024 04:16:48 Ping Of Death from 83.243.123.42 to 공유기 droped
10/13/2024 04:26:46 Ping Of Death from 52.81.253.27 to 공유기 droped
10/13/2024 04:31:28 Ping Of Death from 46.197.151.252 to 공유기 droped
10/13/2024 04:44:35 Ping Of Death from 44.223.77.145 to 공유기 droped
10/13/2024 04:46:27 Ping Of Death from 82.117.252.121 to 공유기 droped
10/13/2024 04:48:09 Ping Of Death from 61.147.171.2 to 공유기 droped
10/13/2024 04:54:17 Ping Of Death from 172.104.94.121 to 공유기 droped
10/13/2024 05:29:15 Ping Of Death from 107.20.15.252 to 공유기 droped
10/13/2024 05:38:35 Ping Of Death from 45.205.128.35 to 공유기 droped
10/13/2024 05:42:39 Ping Of Death from 43.130.90.69 to 공유기 droped
10/13/2024 05:45:36 Ping Of Death from 119.188.182.154 to 공유기 droped
10/13/2024 05:52:47 Ping Of Death from 222.175.101.108 to 공유기 droped
10/13/2024 05:53:48 Ping Of Death from 38.54.114.144 to 공유기 droped
10/13/2024 06:03:50 Ping Of Death from 117.144.213.77 to 공유기 droped
10/13/2024 06:21:56 Ping Of Death from 111.6.188.167 to 공유기 droped
10/13/2024 06:25:25 Ping Of Death from 154.213.184.3 to 공유기 droped
10/13/2024 06:46:30 Ping Of Death from 37.221.111.109 to 공유기 droped
10/13/2024 06:49:35 Ping Of Death from 43.156.12.125 to 공유기 droped
10/13/2024 06:56:27 Ping Of Death from 194.156.155.240 to 공유기 droped
10/13/2024 07:24:58 Ping Of Death from 43.192.8.195 to 공유기 droped
10/13/2024 07:39:32 Ping Of Death from 118.113.198.159 to 공유기 droped
10/13/2024 07:53:38 Ping Of Death from 54.222.204.141 to 공유기 droped
10/13/2024 08:00:06 Ping Of Death from 34.246.194.243 to 공유기 droped
10/13/2024 08:01:50 Ping Of Death from 219.151.22.113 to 공유기 droped
10/13/2024 08:03:50 Ping Of Death from 154.213.184.3 to 공유기 droped
10/13/2024 08:10:21 Ping Of Death from 185.237.185.78 to 공유기 droped
10/13/2024 08:17:06 Ping Of Death from 195.123.211.33 to 공유기 droped
10/13/2024 08:22:53 Ping Of Death from 103.127.124.47 to 공유기 droped
10/13/2024 08:25:56 Ping Of Death from 101.6.8.174 to 공유기 droped
10/13/2024 08:39:48 Ping Of Death from 116.142.242.181 to 공유기 droped
10/13/2024 09:03:03 Ping Of Death from 27.148.249.65 to 공유기 droped
10/13/2024 09:03:32 Ping Of Death from 208.115.230.98 to 공유기 droped
10/13/2024 09:09:18 Ping Of Death from 170.39.227.143 to 공유기 droped
10/13/2024 09:21:47 Ping Of Death from 52.200.19.184 to 공유기 droped
10/13/2024 09:23:51 Ping Of Death from 170.106.14.53 to 공유기 droped
10/13/2024 09:27:10 Ping Of Death from 52.80.238.175 to 공유기 droped
10/13/2024 09:30:59 Ping Of Death from 43.156.12.125 to 공유기 droped
10/13/2024 09:47:48 Ping Of Death from 91.148.134.214 to 공유기 droped
10/13/2024 09:54:43 Ping Of Death from 59.80.30.244 to 공유기 droped
10/13/2024 10:15:41 Ping Of Death from 103.199.18.125 to 공유기 droped
10/13/2024 10:26:05 Ping Of Death from 102.213.6.53 to 공유기 droped
10/13/2024 10:32:06 Ping Of Death from 54.225.49.201 to 공유기 droped
10/13/2024 10:33:10 Ping Of Death from 71.136.112.66 to 공유기 droped
10/13/2024 11:05:44 Ping Of Death from 61.147.171.3 to 공유기 droped
10/13/2024 11:06:26 Ping Of Death from 107.155.46.37 to 공유기 droped
10/13/2024 11:14:04 Ping Of Death from 89.31.122.134 to 공유기 droped
10/13/2024 11:15:30 Ping Of Death from 38.54.38.58 to 공유기 droped
10/13/2024 11:23:57 Ping Of Death from 36.99.169.39 to 공유기 droped
10/13/2024 11:54:01 Syn flood From IP 45.148.10.81 port 27769 to IP 공유기 port 53 droped
10/13/2024 11:54:01 Vecna Scan from IP 45.148.10.81 port 27769 to IP 공유기 port 53 droped
10/13/2024 12:40:00 Ping Of Death from 52.81.237.148 to 공유기 droped
10/13/2024 12:48:52 Ping Of Death from 13.114.34.80 to 공유기 droped
10/13/2024 12:50:36 Ping Of Death from 162.62.58.193 to 공유기 droped
10/13/2024 12:54:46 Ping Of Death from 35.172.109.225 to 공유기 droped
10/13/2024 12:57:26 Ping Of Death from 27.159.66.79 to 공유기 droped
10/13/2024 13:01:27 Ping Of Death from 195.49.210.25 to 공유기 droped
10/13/2024 13:01:36 Ping Of Death from 208.115.216.193 to 공유기 droped
10/13/2024 13:16:00 Ping Of Death from 43.128.69.194 to 공유기 droped
세상의모든계산기 님의 최근 댓글
3×3 이상인 행렬의 행렬식 determinant https://allcalc.org/50536 2025 12.30 답에 이상한 숫자 14.2857142857가 들어간 것은 조건식에 소숫점(.) 이 들어가 있기 때문에 발생한 현상이구요. 100÷7 = 14.285714285714285714285714285714 소숫점 없이 분수로 식이 주어졌을 때와 결과적으로는 동일합니다. 2025 12.30 그럼 해가 무한히 많은지 아닌지 어떻게 아느냐? 고등학교 수학 교과과정에 나오는 행렬의 판별식(d, determinant)을 이용하면 알 수 있습니다. ㄴ 고교과정에서는 2x2 행렬만 다루던가요? 연립방정식의 계수들로 행렬을 만들고 그 행렬식(determinant)을 계산하여야 합니다. 행렬식이 d≠0 이면 유일한 해가 존재하고, d=0 이면 해가 없거나 무수히 많습니다. * 정상적인 경우 (`2y + 8z = 115`)의 계수 행렬: 1 | 1 1 0 | 2 | 1 0 -3.5 | 3 | 0 2 8 | 행렬식 값 = 1(0 - (-7)) - 1(8 - 0) = 7 - 8 = -1 (0이 아니므로 유일한 해 존재) * 문제가 된 경우 (`2y + 7z = 100`)의 계수 행렬: 1 | 1 1 0 | 2 | 1 0 -3.5 | 3 | 0 2 7 | 행렬식 값 = 1(0 - (-7)) - 1(7 - 0) = 7 - 7 = 0 (0이므로 유일한 해가 존재하지 않음) 2025 12.30 좀 더 수학적으로 말씀드리면 (AI Gemini 참고) 수학적 핵심 원리: 선형 독립성(Linear Independence) 3원 1차 연립방정식에서 미지수 x, y, z에 대한 단 하나의 해(a unique solution)가 존재하기 위한 필수 조건은 '주어진 세 개의 방정식이 서로 선형 독립(linearly independent) 관계에 있어야 한다'는 것입니다. * 선형 독립 (Linearly Independent): 어떤 방정식도 다른 방정식들의 조합(상수배를 더하거나 빼는 등)으로 만들어질 수 없는 상태입니다. 기하학적으로 이는 3개의 평면(각 방정식은 3D 공간의 평면을 나타냄)이 단 한 개의 점(해)에서 만나는 것을 의미합니다. * 선형 종속 (Linearly Dependent): 하나 이상의 방정식이 다른 방정식들의 조합으로 표현될 수 있는 상태입니다. 이 경우, 새로운 정보를 제공하지 못하는 '잉여' 방정식이 존재하는 것입니다. 기하학적으로 이는 3개의 평면이 하나의 선에서 만나거나(무수히 많은 해), 완전히 겹치거나, 혹은 평행하여 만나지 않는(해가 없음) 상태를 의미합니다. 질문자님의 사례는 '선형 종속'이 되어 무수히 많은 해가 발생하는 경우입니다. 2025 12.30 질문하신 연립 방정식은 미지수가 3개이고 모두 1차인 3원 1차 연립방정식입니다. 이상적으로 문제가 없다면 {x,y,z} 에 대한 좌표가 하나 나오게 됩니다. 원하는 답 {52.5, -2.5, 15} 그런데 '두개 조건(식)을 그대로 두고 나머지 하나를 변형하다 보니, 원하는 답이 나오지 않는 상황이 발생하였다.'고 질문하신 상황입니다. 3개의 조건식이 주어진 3원 1차 연립방정식은 조건을 변형해서 하나의 변수를 제거할 수 있습니다. 그러면 2개의 조건식으로 주어지는 2원 1차 연립방정식으로 변형이 됩니다. ㄴ 꼭 변형해야하는 것은 아니지만, 이것이 알아보기 쉽기 때문에 변형시키는 것입니다. 변경하지 않은 2개 조건의 식(con1) 을 이용해 위와 같이 하나의 y & z 1차 방정식을 유도할 수 있는데요. 변경하는 나머지 1개의 방정식이 con1에서 유도된 방정식과 동일하다면 하나의 답이 구해지지 않는 상황이 발생하는 것입니다. 계산기(ti-nspire)는 {x,y,z} 의 답이 하나가 아니고 무수히 많음을 c1 을 이용해서 표현해 준 것입니다. linear_independence_cond12.tns 2025 12.30