{"id":2012,"date":"2019-10-12T22:26:32","date_gmt":"2019-10-12T13:26:32","guid":{"rendered":"http:\/\/141.164.34.82\/?p=2012"},"modified":"2019-10-12T22:31:32","modified_gmt":"2019-10-12T13:31:32","slug":"%eb%8f%84%eb%8c%80%ec%b2%b4-%ea%b7%b8%eb%9e%98%eb%94%94%ec%96%b8%ed%8a%b8%ea%b0%80-%eb%ac%b4%ec%97%87%ec%9d%b8%ea%b0%80","status":"publish","type":"post","link":"http:\/\/ds.sumeun.org\/?p=2012","title":{"rendered":"\ub3c4\ub300\uccb4 \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \ubb34\uc5c7\uc778\uac00?"},"content":{"rendered":"

\uc9c8\ubb38: \uadf8\ub798\ub514\uc5b8\ud2b8\ub780 \ubb34\uc5c7\uc778\uac00?[1]<\/sup><\/h2>\n

[1]:<\/sup> \uc774 \uae00\uc758 \uc77c\ubd80\ub294 \ucd9c\uac04 \uc608\uc815\uc778 <\uc218\ud559\uc758 \uc228\uc740 \uc6d0\ub9ac 2><\/strong>\uc758 \uc6d0\uace0 \uc77c\ubd80\ub97c \ubc1c\ucdcc\ud55c \uac83\uc785\ub2c8\ub2e4.<\/p>\n

\uc77c\uc804\uc5d0 facebook\uc5d0\uc11c \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \ubb34\uc5c7\uc778\uc9c0\uc5d0 \ub300\ud574 \ud55c\ucc3d \ub17c\ub780\uc774 \uc788\uc5c8\ub2e4. \uc5b4\ub5a4 \uc0ac\ub78c\ub4e4\uc740 \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \uae30\uc6b8\uae30<\/strong>\ub77c\uace0 \ud558\uace0, \uc5b4\ub5a4 \uc0ac\ub78c\uc740 \ub2e8\uc21c\ud788 \ubc29\ud5a5<\/strong>\uc774\ub77c\uace0 \ud588\ub2e4. \uadf8\ub9ac\uace4 \ub2e4\ub978 \uc0ac\ub78c\uc774 \uacf5\uc2dd \ud558\ub098\ub97c \ubcf4\uc5ec\uc8fc\ub294 \uac83\uc73c\ub85c \ud6c8\ud6c8\ud788(?) \ub9c8\ubb34\ub9ac\uac00 \ub418\uc5c8\ub2e4. (\uadf8\ub807\uc9c0! \uc218\ud559\uc774\ub780 \ubaa8\ub984\uc9c0\uae30 \uacf5\uc2dd\uc73c\ub85c \ub9d0\ud558\ub294 \uac83\uc774\ub2e4!?)<\/p>\n

\uadf8\ub7f0\ub370 \uc815\ub9d0\ub85c, \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \ubb34\uc5c7\uc778\uac00?<\/p>\n

\uc218\ud559\uc740 \uae30\ud638\uc77c \ubfd0\uc774\uc9c0\ub9cc, \uc0c1\uc0c1\ud560 \uc218 \uc788\ub2e4\uba74 \uc27d\ub2e4.<\/h3>\n

\uc0ac\uc2e4 \uc218\ud559\uc790\ub4e4\uc774 \uc5c4\ubc00\ud558\uac8c \uc0dd\uac01\ud558\ub294 \uc218\ud559\uc774\ub780, \uc544\ub2c8 \uc801\uc5b4\ub3c4 \uc99d\uba85\uc744 \ud560\ub54c\uc5d0\ub294, \ub2e8\uc21c\ud788 \uae30\ud638\uc758 \ub098\uc5f4\uc774\ub77c\uc11c \uadf8\uac78 \uc5b4\ub5bb\uac8c \uc0dd\uac01\ud574 \ub0c8\uac74, \uc5b4\ub5bb\uac8c \uc0c1\uc0c1\ud574 \ud574\ub0c8\uac74 \uc0c1\uad00 \uc5c6\ub2e4(\uc8fc\uc5b4\uc9c4 \uacf5\ub9ac\uc640 \ud0c0\ub2f9\ud55c \uc5f0\uc5ed \uaddc\uce59\uc744 \uc0ac\uc6a9\ud558\uae30\ub9cc \ud558\uba74 \ub41c\ub2e4).<\/p>\n

\uc608\ub97c \ub4e4\uc5b4 1+1=2\uc774\uace0, \uc774\uac78 \uc810 2\uac1c\ub85c \uc0c1\uc0c1\ud558\uac74, \uc544\uc774\uc2a4\ud06c\ub9bc 2\uac1c\ub85c \uc0dd\uac01\ud558\uac74 \ubb38\uc81c\uac00 \uc5c6\ub2e4. \uc0ac\uc2e4 \uc810 2\uac1c, \uc544\uc774\uc2a4\ud06c\ub9bc 2\uac1c, \uc0ac\ud0d5 2\uac1c, \ub9c9\ub300 2\uac1c\uc5d0\uc11c \uc218 2\ub97c \ucd94\ucd9c\ud574\ub0b4\ub294 \uac83\ub3c4 \uad49\uc7a5\ud55c \ucd94\uc0c1\ud654, \uc77c\ubc18\ud654 \uacfc\uc815\uc774 \ud544\uc694\ud558\ub2e4. \uadf8\ub798\uc11c \uc5c4\ubc00\ud558\uac8c \ub9d0\ud574, 1+1=2\uc640 \uc544\uc774\uc2a4\ud06c\ub9bc 1\uac1c\uc640 \uc544\uc774\uc2a4\ud06c\ub9bc 1\uac1c\ub97c \ud569\uce58\uba74 \uc544\uc774\uc2a4\ud06c\ub9bc\uc774 2\uac1c\ub77c\ub294 \uba85\uc81c\ub294 a-a=0\uacfc 3-3=0\ub9cc\ud07c\uc774\ub098 \ud070 \uac04\uadf9\uc774 \uc788\ub2e4(\ub77c\uace0 \uc0dd\uac01\ud558\uc9c0\ub9cc,). \uacc4\uc0b0\uc744 \ube68\ub9ac\ud558\uae30 \uc704\ud574 \uc8fc\ud310\uc744 \uc190\uac00\ub77d\uc73c\ub85c \uc624\ub974\ub77d \ub0b4\ub9ac\ub77d\ud55c\ub2e4\uace0 \uafb8\uc911\ud560 \uc0ac\ub78c\ub3c4 \uc5c6\ub2e4(\ubb3c\ub860 \uc8fc\ud310\uc744 \uc0ac\uc6a9\ud558\ub294 \ub300\ubd80\ubd84\uc758 \uacbd\uc6b0\ub294 \uc2e4\uc81c \uc0ac\ubb3c\uc774\ub098 \ub3c8\uc744 \ub300\uc0c1\uc73c\ub85c \ud558\ub294 \uac83\uc774\uaca0\uc9c0\ub9cc).<\/p>\n

\ub300\uc218\uc640 \uae30\ud558<\/h3>\n

\uadf8\ub7fc\uc5d0\ub3c4 \ubd88\uad6c\ud558\uace0 \ub370\uce74\ub974\ud2b8\ub294 \uae30\ud558\uc758 \ub300\uc218\ud654<\/strong>\uc5d0 \uc131\uacf5\ud588\uc73c\uba70, \uc6b0\ub9ac\ub294 \\(2x+2y=0\\) \ub97c 2\ucc28\uc6d0 \ud3c9\uba74 \uc704\uc758 \uc9c1\uc120\uc744 \ub098\ud0c0\ub0b8\ub2e4\uace0 \uc0dd\uac01\ud560 \uc218 \uc788\ub2e4. \uadf8\ub9ac\uace0 \ub300\uc218\ud654\ub41c \uae30\ud558\uc758 \uc911\uc694\uc131\uc740 4\ucc28\uc6d0, 5\ucc28\uc6d0\ucc98\ub7fc \ub208\uc73c\ub85c \ubcfc \uc218\ub3c4 \uc5c6\uace0, \uc9c1\uad00\uc801\uc73c\ub85c \uc0c1\uc0c1\ud560 \uc218\ub3c4 \uc5c6\ub294 \ub300\uc0c1\uc744 \ud0d0\uad6c\ud560 \ub54c \ub4dc\ub7ec\ub09c\ub2e4.<\/p>\n

\uadf8\ub798\uc11c \uadf8\ub798\ub514\uc5b8\ud2b8\ub780 \ubb34\uc5c7\uc778\uac00?<\/h2>\n

\uadf8\ub798\ub514\uc5b8\ud2b8\ub294 1\ubcc0\uc218 \ud568\uc218 \uadf8\ub798\ud504\uc5d0\uc11c \uae30\uc6b8\uae30\uc640 \ube44\uc2b7\ud55c \uc5ed\ud560\uc744 \ud558\ub294\ub370, \uae30\uc6b8\uae30\ub77c\uace0 \ub9d0\ud558\uae34 \ud798\ub4e4\ub2e4. \uc65c\ub0d0\ud558\uba74 \uc704\uc5d0\uc11c \uc598\uae30\ud55c \ud1a0\ub860\uc5d0\uc11c\ub3c4 \uc9c0\uc801\ub418\uc5c8\ub4ef\uc774 \uc5ec\ub7ec \uac12\uc73c\ub85c \uc774\ub8e8\uc5b4\uc9c4 \ubca1\ud130<\/strong>\uc774\uae30 \ub54c\ubb38\uc774\ub2e4. \ubca1\ud130\ub294 \ud754\ud788 \ubc29\ud5a5<\/strong>\uacfc \ud06c\uae30<\/strong>\ub97c \ub3d9\uc2dc\uc5d0 \ub098\ud0c0\ub0b8\ub2e4\uace0 \ub9d0\ud55c\ub2e4.<\/p>\n

\uadf8\ub798\uc11c \ub2e4\ub978 \uc0ac\ub78c\uc740 \uadf8\ub798\ub514\uc5b8\ud2b8\ub294 \uae30\uc6b8\uae30\uac00 \uc544\ub2c8\ub77c \uc21c\uac04\ubcc0\ud654\uc728\uc774 \uac00\uc7a5 \ud070 \ubc29\ud5a5\uc744 \ub098\ud0c0\ub0b8\ub2e4\uace0 \uc8fc\uc7a5\ud588\ub2e4. \uc77c\ub9ac\uac00 \uc788\ub294 \ub9d0\uc774\ub2e4. \uadf8\ub798\ub514\uc5b8\ud2b8 \ub514\uc13c\ud2b8\uc5d0\uc11c\ub3c4 \uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \uc4f0\ub294 \uc774\uc720\ub294 \ud568\uc218\uac12\uc744 \ucd5c\ub300\ud55c \ube60\ub974\uac8c \uac10\uc18c\uc2dc\ud0a4\uae30 \uc704\ud574\uc11c\uc774\ub2e4. \ud568\uc218\uac12\uc744 \ubcc0\ud654\uc2dc\ud0a4\ub824\uba74 \uc785\ub825\uac12\uc744 \ubcc0\ud654\uc2dc\ucf1c\uc57c \ud558\uace0, \uc785\ub825\uac12\uc744 \uc5b4\ub5a4 \uc2dd\uc73c\ub85c \ubcc0\ud654\uc2dc\ucf1c\uc57c \ud568\uc218\uac12\uc744 \uac00\uc7a5 \ube60\ub974\uac8c \ucd5c\uc18c\ud654\ud560 \uc218 \uc788\ub294\uc9c0\ub97c \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \uc54c\ub824\uc8fc\ub294 \uac83\uc774\ub2e4. \ud558\uc9c0\ub9cc \uadf8\ub798\ub514\uc5b8\ud2b8\ub77c\ub294 \ubca1\ud130 \ud568\uc218\ub294 \uc785\ub825\uac12\uc774 \uc8fc\uc5b4\uc84c\uc744 \ub54c \ubca1\ud130\ub97c \ucd9c\ub825\ud55c\ub2e4. \uc55e\uc5d0\uc11c \uc598\uae30\ud588\ub4ef\uc774 \ubca1\ud130\ub294 \ubc29\ud5a5\uacfc \ud06c\uae30\ub97c \ub3d9\uc2dc\uc5d0 \uac00\uc9c0\uace0 \uc788\uae30 \ub54c\ubb38\uc5d0 \ub2e8\uc21c\ud788 \uc21c\uac04\ubcc0\ud654\uc728\uc774 \uac00\uc7a5 \ud070 \ubc29\ud5a5\uc774\ub77c\uace0 \ud558\uae30\uc5d0\ub294 \ubb54\uac00 \ubd80\uc871\ud558\ub2e4. <\/p>\n

\ub300\uc218\ud559(Algebra)\uc774\ub780?<\/h3>\n

\uc22b\uc790 2\uac00 \ub3cc 2\uac1c, \uc790\ub3d9\ucc28 2\uac1c, \ubc14\ub098\ub098 2\uac1c\uc758 \ucd94\uc0c1\ud654\/\uc77c\ubc18\ud654\ub77c\uba74, \ub300\uc218\ud559\uc758 \ubcc0\uc218 \\(x\\) \ub294 \uc22b\uc790 \\(1,2,3\\) \ub4f1\uc758 \ucd94\uc0c1\ud654\/\uc77c\ubc18\ud654\ub77c\uace0 \uc0dd\uac01\ud560 \uc218 \uc788\ub2e4. <\/p>\n

\ub300\uc218\ud559\uc5d0\uc11c\uc758 \uad00\uc2ec\uc740 \ubcc0\uc218\uac00 \ud3ec\ud568\ub41c \ub4f1\uc2dd, \ubd80\ub4f1\uc2dd \ub4f1\uc774\uace0, \uc774\ub4e4 \ub4f1\uc2dd, \ubd80\ub4f1\uc2dd\uc740 \uc77c\uc815\ud55c \uc870\uac74\uc744 \ub9cc\uc871\ud558\ub294 \ubaa8\ub4e0 \uad6c\uccb4\uc801\uc778 \uc218<\/strong>\uc5d0 \ub300\ud574 \uc131\ub9bd\ud55c\ub2e4. \uc608\ub97c \ub4e4\uc5b4 \uc720\uba85\ud55c \uc0b0\uc220\ud3c9\uade0\uacfc \uae30\ud558\ud3c9\uade0\uc758 \uad00\uacc4\ub294 0\ubcf4\ub2e4 \ud070 \ubaa8\ub4e0 \uc2e4\uc218\uc5d0 \ub300\ud574 \uc131\ub9bd\ud558\uace0, \uadf8\uac83\uc744 \uc99d\uba85\ud560 \uc218 \uc788\ub2e4!<\/p>\n

\\[\\frac{a+b}{2} \\geq \\sqrt{ab} \\ \\ (a \\geq 0, b \\geq 0)\\]<\/p>\n

\uc6b0\uc640! \uc2e0\uae30\ud558\ub2e4. \uc5b4\ub5bb\uac8c \ubaa8\ub4e0 \uc591\uc218<\/strong>\uc5d0 \ub300\ud574 \uc704\uc758 \ub4f1\uc2dd \uc131\ub9bd\ud55c\ub2e4\ub294 \uac83\uc744 \uc54c\uc558\ub370?<\/p>\n

\uc0ac\uc2e4 \ub300\uc218\ud559\uc774 \uae30\ud638\ub97c \uc0ac\uc6a9\ud558\uae30 \ub54c\ubb38\uc5d0 \uad6c\uccb4\uc801\uc778 \uc218\ub97c \uc0ac\uc6a9\ud558\ub358 \uc0ac\ub78c\ub4e4\uc5d0\uac8c \uc5b4\ub835\uac8c \ubcf4\uc77c \uc218\ub3c4 \uc788\uc9c0\ub9cc, \uadf8 \uae30\ud638\uac00 \ubb34\uc5c7\uc744 \uc758\ubbf8\ud558\ub294\uc9c0\uc640 \uc0c1\uad00\uc5c6\uc774 \uc77c\uc815\ud55c \uacf5\uc2dd \ub610\ub294 \ubc29\ubc95\uc744 \ub530\ub77c \ubcc0\ud615\uc744 \ud558\uba74 \ub418\uae30 \ub54c\ubb38\uc5d0 \ub300\uc218\ud559\uc758 \ubb38\uc81c\ub294 \ucef4\ud4e8\ud130\ub3c4 \uc27d\uac8c \ud560 \uc218 \uc788\ub294 \ub2e8\uc21c\ud55c \uc791\uc5c5\ub3c4 \ub9ce\ub2e4.<\/p>\n

\uc2e4\uc81c\ub85c \ub300\uc218\ud559\uc5d0\uc11c \uc0ac\uc6a9\ud558\ub294 \uac00\uc7a5 \uae30\ubcf8\uc801\uc778 \uaddc\uce59(\uacf5\ub9ac)\uc740 10\uac1c\ub97c \ub118\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n

\uc5b4\uca0b\ub4e0 \ub300\uc218\ud559\uc740 \ubaa8\ub4e0 \uc218<\/strong> \ub610\ub294 \ud2b9\uc815\ud55c \uc870\uac74\uc744 \ub9cc\uc871\ud558\ub294 \ubaa8\ub4e0 \uc218<\/strong>\uc5d0\uc11c \uc131\ub9bd\ud558\ub294 \ub4f1\uc2dd, \ubd80\ub4f1\uc2dd \ub4f1\uc744 \ubc1d\ud78c\ub2e4.<\/p>\n

\uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \uc124\uba85\ud574 \ub2ec\ub77c\uace0?!!!<\/h3>\n

\uc11c\ub860\uc774 \uae38\uc5c8\ub2e4. \uadf8\ub798\ub514\uc5b8\ud2b8<\/strong>\ub780 \ub2e4\ubcc0\uc218 \ud568\uc218\uc758 \ubaa8\ub4e0 \uc785\ub825\uac12<\/strong>\uc5d0\uc11c \ubaa8\ub4e0 \ubc29\ud5a5<\/strong>\uc5d0 \ub300\ud55c \uc21c\uac04\ubcc0\ud654\uc728<\/strong>\uc774\ub2e4.<\/p>\n

\uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \uacc4\uc0b0\ud558\uae30 \uc704\ud574\uc11c\ub294 \uc77c\ub2e8 \ud568\uc218\uac00 \ud544\uc694\ud558\ub2e4. <\/p>\n

\uc6b0\uc120 1\ucc28\uc6d0 \ud568\uc218\uc5d0 \ub300\ud55c \ubbf8\ubd84\uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \uba87\uba87 \uc0ac\ub78c\ub4e4\uc740 \ubbf8\ubd84\uc744 \ub2e8\uc21c\ud788 \uae30\uc6b8\uae30\ub77c\uace0 \ub9d0\ud558\ub294\ub370, \ud568\uc218\ub97c \ubbf8\ubd84\ud55c \uacb0\uacfc\ub294 \uae30\ud558\ud559\uc801\uc778 \uae30\uc6b8\uae30\ub97c \uacc4\uc0b0\ud560 \uc218 \uc788\ub294 \ud568\uc218\uc774\ub2e4.<\/p>\n

\uc608\ub97c \ub4e4\uc5b4 \\(f(x)=x^2\\) \uc758 \ubbf8\ubd84 \ud568\uc218\uc778 \\(f'(x)=2x\\) \ub294 \uc810 0\uc5d0\uc11c \uae30\uc6b8\uae30\uac00 0, \uc810 1\uc5d0\uc11c\ub294 \uae30\uc6b8\uae30\uac00 \\(2\\cdot 1= 2\\) \uc784\uc744 \uc54c\ub824\uc8fc\uace0, \uc774 \ud568\uc218\ub294 \ubaa8\ub4e0 \uc810\uc5d0\uc11c\uc758 \uae30\uc6b8\uae30(\uc21c\uac04\ubcc0\ud654\uc728)\uc744 \uc54c\ub824\uc8fc\ub294 \ud568\uc218\uc774\ub2e4. (\uc5b4\ub5bb\uac8c \ubcc0\uc218\ub97c \ud65c\uc6a9\ud558\uc5ec \ubaa8\ub4e0 \uc785\ub825\uac12<\/strong>\uc5d0 \ub300\ud574 \uc21c\uac04\ubcc0\ud654\uc728\uc744 \uc54c\ub824\uc8fc\ub294\uc9c0 \uc74c\ubbf8\ud574\ubcf4\uc790.)<\/p>\n

\uadf8\ub798\ub514\uc5b8\ud2b8\ub294 \uc8fc\uc5b4\uc9c4 \ub2e4\ubcc0\uc218 \ud568\uc218\uc5d0 \ub300\ud574 \ubca1\ud130 \ud568\uc218\uac00 \ub41c\ub2e4. \ud2b9\uc815\ud55c \uc785\ub825\uac12\uc5d0 \ub300\ud574 \ubca1\ud130\ub97c \uc0b0\ucd9c\ud558\ubbc0\ub85c \ud655\uc2e4\ud788 \uc21c\uac04\ubcc0\ud654\uc728\uc774\ub77c\uace0 \ub9d0\ud558\uae30\uc5d4 \uc5b4\ub518\uac00 \ubd80\uc871\ud558\ub2e4.<\/p>\n

\uadf8\ub798\ub514\uc5b8\ud2b8\ub294 \uc815\ud655\ud55c \uc758\ubbf8\ub294 \ub2e4\uc74c\uc758 \uc2dd\uc5d0\uc11c \uc880 \ub354 \uc0b4\ud3b4\ubcfc \uc218 \uc788\ub2e4. <\/p>\n

\\[f(\\vec{x}+\\vec{\\epsilon}) \\approx f(\\vec{x}) + \\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\]<\/p>\n

\uc810 \\(\\vec{x}\\) \uc5d0\uc11c \ub9e4\uc6b0 \uc791\uc740 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \uc704\uc758 \ub4f1\uc2dd\uc774 \uc131\ub9bd\ud55c\ub2e4. (\uc65c\ub0d0\ud558\uba74 \uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \uc815\uc758\ud560 \ub54c \uc800\uac8c \uc131\ub9bd\ud558\ub3c4\ub85d \ud588\uae30 \ub54c\ubb38\uc774\uace0 \uc800\ub7f0 \uc2dd\uc774 \uc131\ub9bd\ud558\uc9c0 \uc54a\ub294\ub2e4\uba74 \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \uc874\uc7ac\ud558\uc9c0 \uc54a\ub294\ub2e4<\/strong>.)<\/p>\n

\uc800 \uc2dd\uc5d0 \ub530\ub974\uba74 \ud2b9\uc815\ud55c \ubc29\ud5a5\uc758 \uc21c\uac04\ubcc0\ud654\uc728\uc744 \uc54c\uace0 \uc2f6\ub2e4\uba74 \\(\\vec{\\epsilon}\\) \ub300\uc2e0\uc5d0 \uadf8 \ubc29\ud5a5\uc758 \uae38\uc774\uac00 1\uc778 \ubca1\ud130\ub97c \ub300\uc785\ud558\uba74 \ub41c\ub2e4. \uadf8\ub9ac\uace0 \uc5b4\ub5a4 \ubc29\ud5a5\uc5d0 \ub300\ud574\uc11c\ub3c4 \uac00\ub2a5\ud558\ub2e4.<\/p>\n

\uc608\ub97c \ub4e4\uc5b4\ubcf4\uc790. \\(f(x_1, x_2) = x_1^2 +x_1x_2+ x_2^2\\) \uc5d0\uc11c \\(\\nabla{f}=(2x_1+x_2, 2x_2+x_1)^\\textrm{T}\\) \uc774\uace0, \\((0,1)\\) \uc5d0\uc11c \\(\\nabla{f}(0,1)=(1,2)\\) \uc774\ub2e4. \uc774\ub54c \\((1,1)\\) \ubc29\ud5a5\uc758 \uc21c\uac04 \ubcc0\ud654\uc728\uc744 \uc54c\uace0 \uc2f6\ub2e4\uba74, \\((1,2)\\cdot (1\/\\sqrt{2},1\/\\sqrt{2})=3\/\\sqrt{2}\\) \uac00 \ub41c\ub2e4. <\/p>\n

\uc5b4\ub5a4 \ubc29\ud5a5\uc73c\ub85c\uc758 \uc21c\uac04\ubcc0\ud654\uc728\uc774\ub780 1\ubcc0\uc218 \ud568\uc218\ub97c \uc0dd\uac01\ud574\ubcf4\uba74 \uc26c\uc6b8 \uc218 \uc788\ub2e4. <\/p>\n

\\((1,1)\\) \ubc29\ud5a5\uc73c\ub85c \\((x_1, x_2)\\) \uac00 \ubcc0\ud55c\ub2e4\uba74, \\((x_1, x_2) = t(1,1) = (t,t)\\) \ub85c \uc4f8 \uc218 \uc788\ub2e4. \uc774\ub294 \\((0,0)\\) \uc744 \uc9c0\ub098\uac00\ub294 \uacbd\uc6b0\uc774\uace0, \\((0,1)\\) \uc744 \uc9c0\ub098\uac00\ub824\ud55c\ub2e4\uba74 \\((x_1, x_2) = (t,t)+(0,1)\\) \ub85c \uc4f8 \uc218 \uc788\ub2e4. \uadf8\ub54c \\(f(x_1, x_2) = x_1^2+x_1x_2+x_2^2=t^2+t\\cdot(t+1)+(t+1)^2\\) \uc774 \ub41c\ub2e4.<\/p>\n

\\(f(x_1,x_2)=f(t)=t^2+t(t+1)+(t+1)^2=t^2+t^2+t+t^2+2t+1=3t^2+3t+1\\) \uc774 \ub418\uace0, \uc774\ub97c \ubbf8\ubd84\ud558\uba74, \\(f'(t) = 6t+3\\) \uc774\ub2e4. \uc810 \\((0,1)\\) \uc740 \\(t=0\\) \uc77c \ub54c \uc9c0\ub098\uac04\ub2e4. \\(f'(0)=3\\) . <\/p>\n

\uadf8\ub7f0\ub370 \\(t\\) \uac00 \\(1\\) \ub9cc\ud07c \uc6c0\uc9c1\uc77c \ub54c \\((t,t+1)\\) \uc740 \uae38\uc774 \\(\\sqrt{2}\\) \ub9cc\ud07c \uc6c0\uc9c1\uc774\ubbc0\ub85c \uc774\ub97c \ubcf4\uc815\ud558\uba74 \\(f(t)\\) \uc758 \uc21c\uac04\ubcc0\ud654\uc728(\ub2e4\uc2dc \ub9d0\ud574 \\(f(\\vec{x})\\) \uc758 \\((1,1)\\) \ubc29\ud5a5 \uc21c\uac04\ubcc0\ud654\uc728)\uc740 \\(3\/\\sqrt{2}\\) \uac00 \ub41c\ub2e4!<\/p>\n

\"\"\/<\/p>\n

\"\"\/<\/p>\n

\"\"\/<\/p>\n

# cocalc.com\n# Sage Worksheet\nvar('x y z')\np1 = implicit_plot3d(x^2+x*y+y^2==z, (x,-3,3), (y,-3,3), (z,-3,3), texture='blue', mesh=True)\np2 = implicit_plot3d(x+2*(y-1)==(z-1), (x,-3,3), (y,-3,3), (z,-3,3), texture='red', mesh=True)\np3 = implicit_plot3d(x==0, (x,-3,3), (y,-3,3), (z,-3,3), alpha=0.2)\np4 = implicit_plot3d(y==1, (x,-3,3), (y,-3,3), (z,-3,3), alpha=0.2)\np1 + p2 + p3 + p4\n<\/pre>\n
\ub2e4\ub978 \ubc29\ud5a5\uc73c\ub85c\uc758 \uc21c\uac04\ubcc0\ud654\uc728\ub3c4 \uacc4\uc0b0\ud574\ubcf4\uc790. \uadf8\ub798\ub514\uc5b8\ud2b8\ub85c \uacc4\uc0b0\ud574\ubcf4\uace0, \uc774\ubcc0\uc218 \ud568\uc218\ub97c 1\ubcc0\uc218 \ud568\uc218\ub85c \ub9cc\ub4e4\uc5b4\uc11c\ub3c4 \uacc4\uc0b0\ud574 \ubcf4\uc790.<\/p>\n
\ubaa8\ub4e0 \uac12\uc5d0\uc11c \ubaa8\ub4e0 \ubc29\ud5a5\uc758 \uc21c\uac04\ubcc0\ud654\uc728\uc744 \\(\\nabla{f}(\\vec{x})\\cdot\\vec{\\epsilon}\\) \ub85c \uad6c\ud560 \uc218 \uc788\ub2e4\uace0?<\/h3>\n
\uadf8\ub807\ub2e4! \\(|\\vec{\\epsilon}|=1\\) \uc774\uace0, \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \uc874\uc7ac\ud55c\ub2e4\uba74, \\(\\nabla{f}(\\vec{x})\\cdot\\vec{\\epsilon}\\) \uc740 \ubaa8\ub4e0 \uc810 \\(\\vec{x}\\) \uc5d0\uc11c \ubaa8\ub4e0 \ubc29\ud5a5 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud55c \uc21c\uac04\ubcc0\ud654\uc728\uc744 \ub098\ud0c0\ub0b8\ub2e4. \uc5b4\ub5bb\uac8c \uadf8\uac8c \uac00\ub2a5\ud558\ub0d0\uace0? \uadf8\ub798\ub514\uc5b8\ud2b8\uc758 \ud2b9\uc9d5\uc774\uace0 \ubcc0\uc218\uc758 \ud45c\ud604\ub825\uc774\ub2e4!<\/p>\n
\ub9cc\uc57d \\(|\\vec{\\epsilon}|=1\\) \uc744 \ub9cc\uc871\ud558\uc9c0 \uc54a\ub294\ub2e4\uba74 \\(\\nabla{f}(\\vec{x})\\cdot\\vec{\\epsilon}\\) \ub294 \uc785\ub825\uac12 \\(\\vec{x}\\) \uc5d0\uc11c\uc758 \uc21c\uac04\ubcc0\ud654\uc728\uc744 \uadf8\ub300\ub85c \uc720\uc9c0\ud558\uba74\uc11c \\(\\vec{\\epsilon}\\) \ub9cc\ud07c \uc785\ub825\uac12\uc744 \ubcc0\ud654\uc2dc\ud0ac \ub54c\uc758 \ubcc0\ud654\ub7c9<\/strong>\uc774\ub77c\uace0 \ub9d0\ud560 \uc218 \uc788\uaca0\ub2e4.<\/p>\n
\uadf8\ub9ac\uace0 \uc774\ub7f0 \ub9e5\ub77d\uc5d0\uc11c \\(f\\) \uc758 \\(\\vec{x}\\) \uc5d0\uc11c \uc21c\uac04\ubcc0\ud654\uc728\uc744 \uae30\uc900\uc73c\ub85c \uac00\uc7a5 \ube60\ub974\uac8c \\(f\\) \ub97c \ubcc0\ud654\uc2dc\ud0a4\ub294 \ubc29\ud5a5\uc740 \\(\\frac{\\nabla f(\\vec{x})}{|\\nabla f(\\vec{x})|}\\) \uc774\uace0(\ubc29\ud5a5\uc744 \ub098\ud0c0\ub0bc \ub54c\uc5d0\ub294 \ubcf4\ud1b5 \uae38\uc774 1\uc778 \ubca1\ud130\ub97c \uc0ac\uc6a9\ud55c\ub2e4), \uadf8\ub54c \uc21c\uac04 \ubcc0\ud654\uc728\uc740 \\(\\nabla f(\\vec{x}) \\cdot \\frac{\\nabla f(\\vec{x})}{|\\nabla f(\\vec{x})|}\\) \uc774 \ub41c\ub2e4. (\ub530\ub77c\uc11c \\(\\nabla f(\\vec{x}) \\cdot \\frac{\\nabla f(\\vec{x})}{|\\nabla f(\\vec{x})|}\\) \ub294 \uc785\ub825\uac12 \\(\\vec{x}\\) \uc5d0\uc11c \ud568\uc218 \\(f\\) \uc758 \ucd5c\ub300<\/strong> \uc21c\uac04\ubcc0\ud654\uc728\uc774\ub77c\uace0\ub3c4 \ud560 \uc218 \uc788\ub2e4.)<\/p>\n
\uc5ec\uae30\uc11c \\(\\frac{\\nabla f(\\vec{x})}{|\\nabla f(\\vec{x})|}\\) \uc740 \\(\\frac{\\vec{a}}{|\\vec{a}|}\\) \uc740 \ubca1\ud130 \\(\\vec{a}\\) \uc640 \ubc29\ud5a5\uc774 \uac19\uace0, \ud06c\uae30\ub294 1\uc778 \ubca1\ud130\uac00 \ub428\uc744 \ud65c\uc6a9\ud55c \uac83\uc774\ub2e4.<\/p>\n
R\uc5d0\uc11c \uadf8\ub798\ub514\uc5b8\ud2b8 \uad6c\ud558\uae30<\/h2>\n
R\uc5d0\uc11c \ubbf8\ubd84 \ub610\ub294 \uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \uad6c\ud558\ub294 \uae30\ubcf8\uc801\uc778 \ud568\uc218\ub294 stats::D<\/code>, stats::deriv<\/code>\uac00 \uc788\ub2e4.<\/p>\n
?D<\/code> \ub610\ub294 ?deriv<\/code>\ub97c \uccd0\ubcf4\uba74, Symbolic and Alorithmic Derivatives of Simple Expressions\ub77c\uace0 \ub098\uc628\ub2e4. \uc5ec\uae30\uc11c Simple Expressions\ub294 +<\/code>, -<\/code>, *<\/code>, \/<\/code>, ^<\/code>, exp<\/code>, log<\/code>, sin<\/code>, cos<\/code>, tan<\/code>, sinh<\/code>, cosh<\/code>, sqrt<\/code>, pnorm<\/code>, dnorm<\/code>, asin<\/code>, acos<\/code>, atan<\/code>, gamma<\/code>, lgamma<\/code>, digamma<\/code>, trigamma<\/code>, psigamma<\/code>(\uccab \ubc88\uc9f8 \uc778\uc790\uc5d0 \ub300\ud574\uc11c), log1p<\/code>, expm1<\/code>, log2<\/code>, log10<\/code>, cospi<\/code>, sinpi<\/code>, tanpi<\/code>, factorial<\/code>, lfactorial<\/code>\uc744 \ud3ec\ud568\ud558\ub294 \uc218\uc2dd\uc774\ub2e4.<\/p>\n
\ub2e4\uc74c\uc740 D<\/code> \ub610\ub294 deriv<\/code>\ub97c \uc0ac\uc6a9\ud558\uc5ec \uac04\ub2e8\ud55c \ud568\uc218\uc758 \ubbf8\ubd84\uc744 \uad6c\ud558\ub294 \uc608\uc774\ub2e4.<\/p>\n
expr <- expression(x^2+2*x*y+y^2)\nD(expr, name='x')\n<\/code><\/pre>\n
## 2 * x + 2 * y\n<\/pre>\n
deriv(expr, namevec=c('x', 'y'))\n<\/code><\/pre>\n
## expression({\n##     .expr2 <- 2 * x\n##     .expr8 <- .expr2 + 2 * y\n##     .value <- x^2 + .expr2 * y + y^2\n##     .grad <- array(0, c(length(.value), 2L), list(NULL, c("x", \n##         "y")))\n##     .grad[, "x"] <- .expr8\n##     .grad[, "y"] <- .expr8\n##     attr(.value, "gradient") <- .grad\n##     .value\n## })\n<\/pre>\n
expression<\/code>, quote<\/code>, \uadf8\ub9ac\uace0 parse<\/code><\/h3>\n
R\uc5d0\uc11c expression\uc740 \uc544\uc9c1 \uacc4\uc0b0\ub418\uc9c0 \uc54a\uc740 \uc218\uc2dd\uc774\ub77c\uace0 \uc0dd\uac01\ud560 \uc218 \uc788\ub2e4. \uc608\ub97c \ub4e4\uc5b4 2*x+y<\/code>\ub97c \uc785\ub825\ud558\uba74 x<\/code>\uc758 \uac12\uacfc y<\/code>\uc758 \uac12\uc774 \ub300\uc785\ub418\uc5b4 2*x+y<\/code>\uc758 \uacb0\uacfc\uac00 \uc0b0\ucd9c\ub41c\ub2e4.<\/p>\n
x=3; y=2\n2*x+y\n<\/code><\/pre>\n
## [1] 8\n<\/pre>\n
\ub9cc\uc57d x<\/code>\uc640 y<\/code>\uc5d0 \uac12\uc774 \ub300\uc785\ub418\uc9c0 \uc54a\uc740 \uc218\uc2dd\uc744 \uadf8\ub300\ub85c \uc800\uc7a5\ud558\uace0 \uc2f6\ub2e4\uba74, expression<\/code> \ub610\ub294 quote<\/code>\ub97c \uc0ac\uc6a9\ud55c\ub2e4.<\/p>\n
a <- expression(2*x+y)\nprint(a)\n<\/code><\/pre>\n
## expression(2 * x + y)\n<\/pre>\n
\uadf8\ub9ac\uace0 \uc774 \uc218\uc2dd\uc5d0 \ub530\ub77c \uc2e4\uc81c \uacc4\uc0b0\uc744 \ud558\uace0 \uc2f6\ub2e4\uba74, eval<\/code> \ud568\uc218\ub97c \uc0ac\uc6a9\ud55c\ub2e4.<\/p>\n
eval(a)\n<\/code><\/pre>\n
## [1] 8\n<\/pre>\n
x=2; y=2;\neval(a)\n<\/code><\/pre>\n
## [1] 6\n<\/pre>\n
D<\/code><\/h3>\n
\ud568\uc218 D<\/code>\ub294 expression\uc5d0 \ub300\ud574 \ud55c \ubcc0\uc218\uc758 \ud3b8\ubbf8\ubd84\uc744 \uad6c\ud55c \uacb0\uacfc\ub97c expression\uc73c\ub85c \ubc18\ud658\ud55c\ub2e4.<\/p>\n
D(expression(y*cos(x)+x*sin(y)), 'x')\n<\/code><\/pre>\n
## sin(y) - y * sin(x)\n<\/pre>\n
\ub9cc\uc57d \ud2b9\uc815 \uc785\ub825\uac12\uc5d0\uc11c\uc758 \ubbf8\ubd84\uac12\uc744 \uad6c\ud558\uace0 \uc2f6\ub2e4\uba74, eval(   , list(x=, y=))<\/code>\ub97c \uc0ac\uc6a9\ud560 \uc218 \uc788\ub2e4.<\/p>\n
f <- expression(y*cos(x)+x*sin(y))\ndfdx <- D(f, 'x')\neval(dfdx, list(x=1, y=pi))\n<\/code><\/pre>\n
## [1] -2.643559\n<\/pre>\n
\uc704\uc758 \\(-2.643559\\) \ub294 \\(y\\cos(x)+x\\sin(y)\\) \uc758 \\(x\\) \ud3b8\ubbf8\ubd84 \\(\\frac{\\partial f(x,y)}{\\partial x} = \\sin(y)-y\\sin(x)\\) \uc758 \\((x,y)=(1,\\pi)\\) \uc5d0\uc11c\uc758 \uac12\uc774\ub2e4.<\/p>\n
\\[\\frac{\\partial f(x,y)}{\\partial x}\\vert_{(x,y)=(1,\\pi)} = \\sin(\\pi)-\\pi\\sin(1) \\approx -2.643559\\]<\/p>\n
deriv<\/code><\/h3>\n
deriv<\/code> \ud568\uc218\ub3c4 expression\uc744 \ubc1b\uc544 expression\uc744 \ubc18\ud658\ud558\ub294\ub370, \uc774 expression\uc740 x<\/code>\uc640 y<\/code>\uac00 \uc8fc\uc5b4\uc84c\uc744 \ub54c, \ud568\uc218\uac12\uacfc \uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \ubaa8\ub450 \uad6c\ud574 \ud558\ub098\uc758 \ubcc0\uc218\ub85c \ubc18\ud658\ud55c\ub2e4.<\/p>\n
f <- expression(y*cos(x)+x*sin(y))\nf2 <- deriv(f, c('x', 'y'))\nf2\n<\/code><\/pre>\n
## expression({\n##     .expr1 <- cos(x)\n##     .expr3 <- sin(y)\n##     .value <- y * .expr1 + x * .expr3\n##     .grad <- array(0, c(length(.value), 2L), list(NULL, c("x", \n##         "y")))\n##     .grad[, "x"] <- .expr3 - y * sin(x)\n##     .grad[, "y"] <- .expr1 + x * cos(y)\n##     attr(.value, "gradient") <- .grad\n##     .value\n## })\n<\/pre>\n
\uc774\ub97c \ud65c\uc6a9\ud558\ub294 \ubc29\ubc95\uc740 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n
eval(f2, list(x=1, y=pi))\n<\/code><\/pre>\n
## [1] 1.69741\n## attr(,"gradient")\n##              x          y\n## [1,] -2.643559 -0.4596977\n<\/pre>\n
\\(y\\cos(x)+x\\sin(y)\\) \uc758 \\((x,y)=(1,\\pi)\\) \uc5d0\uc11c\uc758 \uac12\uc740 \\(1.69741\\) \uc774\uba70, \uadf8\ub798\ub514\uc5b8\ud2b8\ub294 \\((-2.643559, -0.4596977)\\) \uc784\uc744 \uc704\uc758 \uacb0\uacfc\ub85c \uc54c \uc218 \uc788\ub2e4.<\/p>\n
\ud5e4\uc2dc\uc548\uae4c\uc9c0 \uad6c\ud558\uace0\uc790 \ud55c\ub2e4\uba74, deriv3<\/code>\uc744 \uc0ac\uc6a9\ud55c\ub2e4. <\/p>\n
f3 <- deriv3(f, c('x', 'y'))\neval(f3, list(x=1, y=pi))\n<\/code><\/pre>\n
## [1] 1.69741\n## attr(,"gradient")\n##              x          y\n## [1,] -2.643559 -0.4596977\n## attr(,"hessian")\n## , , x\n## \n##             x         y\n## [1,] -1.69741 -1.841471\n## \n## , , y\n## \n##              x             y\n## [1,] -1.841471 -1.224606e-16\n<\/pre>\n
\uadf8 \ubc16\uc5d0<\/h3>\n
\ub2e4\uc74c\uc5d0\uc11c \ubcf4\ub4ef\uc774 expression<\/code>, quote<\/code>, parse<\/code>\ub294 \ubaa8\ub450 \ube44\uc2b7\ud55c \uc5ed\ud560\uc744 \ud558\uace0 \uc788\ub2e4.<\/p>\n
D(expression(x^2*y), 'x')\nD(quote(x^2*y), 'x')\nD(parse(text="x^2*y"), 'x')\n<\/code><\/pre>\n
## 2 * x * y\n## 2 * x * y\n## 2 * x * y\n<\/pre>\n
\uc880 \ub354 expression<\/code>\uacfc quote<\/code>\uc740 \ub2e4\uc74c\uacfc \uac19\uc740 \ucc28\uc774\uac00 \uc788\ub2e4.<\/p>\n
expression(x^2+y^2, 2*x*y)\n<\/code><\/pre>\n
## expression(x^2 + y^2, 2 * x * y)\n<\/pre>\n
quote(x^2+y^2, 2*x*y)\n<\/code><\/pre>\n
## Error in quote(x^2 + y^2, 2 * x * y): 2 arguments passed to 'quote' which requires 1\n<\/pre>\n
quote(x^2+y^2)\n<\/code><\/pre>\n
## x^2 + y^2\n<\/pre>\n
a <- expression(x^2+y^2, 2*x*y)\nb <- quote(x^2+y^2)\nall.equal(a[[1]], b)\n<\/code><\/pre>\n
## [1] TRUE\n<\/pre>\n
R\uc5d0\uc11c \uc218\uce58 \ubbf8\ubd84<\/h2>\n
\ud568\uc218 D<\/code>\uc640 \ud568\uc218 deriv<\/code>\ub294 \uc55e\uc5d0\uc11c \uc5b8\uae09\ub41c \ud568\uc218\uc5d0 \ub300\ud574\uc11c\ub9cc \ubbf8\ubd84\uc774 \uac00\ub2a5\ud558\ub2e4\ub294 \ub2e8\uc810\uc774 \uc788\ub2e4. \uc218\uce58 \ubbf8\ubd84\uc744 \uc0ac\uc6a9\ud558\uba74 \uadf8\ub7f0 \uc81c\uc57d\uc740 \uc5c6\ub2e4. \ubc18\uba74 \ud55c \uc810\uc5d0 \ub300\ud574\uc11c\ub9cc \uacc4\uc0b0\uc774 \uac00\ub2a5\ud558\uba70 D<\/code>\uc640 deriv<\/code>\ucc98\ub7fc \ubaa8\ub4e0 \uc810\uc5d0\uc11c\uc758 \uae30\uc6b8\uae30\ub97c \uad6c\ud558\ub294 \ud568\uc218\ub97c \uad6c\ud558\uc9c0\ub294 \ubabb\ud55c\ub2e4.<\/p>\n
\ub2e4\uc74c\uc740 \ud568\uc218 \\(y\\cos(x)+x\\sin(y)\\) \uc758 \\((1,\\pi)\\) \uc5d0\uc11c \uadf8\ub798\ub514\uc5b8\ud2b8 \uac12\uc744 \uad6c\ud55c\ub2e4. <\/p>\n
library(numDeriv)\n\nf<-function(x) {x[2]*cos(x[1])+x[1]*sin(x[2])}\n\ngrad(f,c(1, pi))\n<\/code><\/pre>\n
## [1] -2.6435591 -0.4596977\n<\/pre>\n
\ub364\uc73c\ub85c \ud5e4\uc2dc\uc548\uacfc \uc790\ucf54\ube44\uc548\uc740 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n
hessian(f,c(1,pi))\n<\/code><\/pre>\n
##           [,1]          [,2]\n## [1,] -1.697410 -1.841471e+00\n## [2,] -1.841471 -2.082973e-13\n<\/pre>\n
g = function(x) { c(x[2]*cos(x[1])+x[1]*sin(x[2]), x[1]^2+x[2]^2)}\njacobian(g, c(1,pi))\n<\/code><\/pre>\n
##           [,1]       [,2]\n## [1,] -2.643559 -0.4596977\n## [2,]  2.000000  6.2831853\n<\/pre>\n
deriv<\/code>\uc640 grad<\/code> \ube44\uad50<\/h3>\n
R\uc758 \ud568\uc218 dgamma<\/code>\ub294 \ub2e4\uc74c\uc758 \ud568\uc218\ub97c \ub098\ud0c0\ub0b8\ub2e4. (\uc774\ub54c \\(k\\) = shape<\/code>, \\(\\theta\\) = scale<\/code>)<\/p>\n
\\[f(x; k, \\theta) = x^{k-1}\\frac{\\exp(-x\/\\theta)}{\\theta^k \\Gamma(k)}\\]<\/p>\n
curve(dgamma(x, shape=2, scale=2), xlim=c(0,10))\n<\/code><\/pre>\n
\"plot<\/p>\n
\\((x,k,\\theta) = (2, 2, 2)\\) \uc5d0\uc11c \uadf8\ub798\ub514\uc5b8\ud2b8\ub97c \uad6c\ud558\uace0\uc790 \ud55c\ub2e4.<\/p>\n
deriv(expression(dgamma(x,k,th)), c('x', 'k', 'th'))\n<\/code><\/pre>\n
## Error in deriv.default(expression(dgamma(x, k, th)), c("x", "k", "th")): Function 'dgamma' is not in the derivatives table\n<\/pre>\n
deriv<\/code>\ub85c\ub294 dgamma<\/code>\uc758 \ubbf8\ubd84\uc774 \ubd88\uac00\ub2a5\ud558\uc9c0\ub9cc grad<\/code>\ub97c \ud1b5\ud55c \uc218\uce58\ubbf8\ubd84\uc740 \uac00\ub2a5\ud558\ub2e4.<\/p>\n
f <- function(x) {\n  dgamma(x[1], x[2], x[3])\n}\ngrad(f, c(2,2,2))\n<\/code><\/pre>\n
## [1] -0.2197877  0.1411784 -0.1465251\n<\/pre>\n
\ud55c \uc904 \uc815\ub9ac<\/h2>\n
\uadf8\ub798\ub514\uc5b8\ud2b8<\/strong>\ub780 \ub2e4\ubcc0\uc218 \ud568\uc218\uc758 \ubaa8\ub4e0 \uc785\ub825\uac12<\/strong>\uc5d0\uc11c \ubaa8\ub4e0 \ubc29\ud5a5<\/strong>\uc73c\ub85c\uc758  \uc21c\uac04\ubcc0\ud654\uc728<\/strong>\uc774\ub2e4. \ubaa8\ub4e0 \ubc29\ud5a5\uc758 \uc21c\uac04\ubcc0\ud654\uc728\uc740 \ud568\uc218 \\(f(\\vec{x})\\) \uc758 \uc5b4\ub5a4 \ud55c \uc810(\ud639\uc740 \ubaa8\ub4e0 \uc810)\uc5d0\uc11c \uc811\ud558\ub294 \uc811\ud3c9\uba74\uc758 \uae30\uc6b8\uae30<\/strong>\uc774\ub2e4. (\uc811\ud3c9\uba74\uc758 \uae30\uc6b8\uae30\ub294 \ubcc0\uc218 \uac2f\uc218\ub9cc\ud07c\uc758 \uc22b\uc790\uac00 \ud544\uc694\ud558\ub2e4.)<\/p>\n","protected":false},"excerpt":{"rendered":"
\uc9c8\ubb38: \uadf8\ub798\ub514\uc5b8\ud2b8\ub780 \ubb34\uc5c7\uc778\uac00?[1] [1]: \uc774 \uae00\uc758 \uc77c\ubd80\ub294 \ucd9c\uac04 \uc608\uc815\uc778 <\uc218\ud559\uc758 \uc228\uc740 \uc6d0\ub9ac 2>\uc758 \uc6d0\uace0 \uc77c\ubd80\ub97c \ubc1c\ucdcc\ud55c \uac83\uc785\ub2c8\ub2e4. \uc77c\uc804\uc5d0 facebook\uc5d0\uc11c \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \ubb34\uc5c7\uc778\uc9c0\uc5d0 \ub300\ud574 \ud55c\ucc3d \ub17c\ub780\uc774 \uc788\uc5c8\ub2e4. \uc5b4\ub5a4 \uc0ac\ub78c\ub4e4\uc740 \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \uae30\uc6b8\uae30\ub77c\uace0 \ud558\uace0, \uc5b4\ub5a4 \uc0ac\ub78c\uc740 \ub2e8\uc21c\ud788 \ubc29\ud5a5\uc774\ub77c\uace0 \ud588\ub2e4. \uadf8\ub9ac\uace4 \ub2e4\ub978 \uc0ac\ub78c\uc774 \uacf5\uc2dd \ud558\ub098\ub97c \ubcf4\uc5ec\uc8fc\ub294 \uac83\uc73c\ub85c \ud6c8\ud6c8\ud788(?) \ub9c8\ubb34\ub9ac\uac00 \ub418\uc5c8\ub2e4. (\uadf8\ub807\uc9c0! \uc218\ud559\uc774\ub780 \ubaa8\ub984\uc9c0\uae30 \uacf5\uc2dd\uc73c\ub85c \ub9d0\ud558\ub294 \uac83\uc774\ub2e4!?) \uadf8\ub7f0\ub370 \uc815\ub9d0\ub85c, \uadf8\ub798\ub514\uc5b8\ud2b8\uac00 \ubb34\uc5c7\uc778\uac00? […]<\/p>\n","protected":false},"author":1,"featured_media":2009,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[319],"tags":[398,309,399,19,400],"jetpack_featured_media_url":"http:\/\/ds.sumeun.org\/wp-content\/uploads\/2019\/10\/gradient_01.png","_links":{"self":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/2012"}],"collection":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2012"}],"version-history":[{"count":3,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/2012\/revisions"}],"predecessor-version":[{"id":2015,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/2012\/revisions\/2015"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/media\/2009"}],"wp:attachment":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2012"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2012"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2012"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}