{"id":3354,"date":"2008-08-26T01:46:00","date_gmt":"2008-08-25T16:46:00","guid":{"rendered":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/?p=3354"},"modified":"2021-09-02T16:23:05","modified_gmt":"2021-09-02T07:23:05","slug":"%eb%af%b8%eb%b6%84%ea%b8%b0%ed%95%98%ed%95%99ii-2k7-%ea%b0%80%ec%9d%84%ed%95%99%ea%b8%b0","status":"publish","type":"post","link":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/2008\/08\/26\/%eb%af%b8%eb%b6%84%ea%b8%b0%ed%95%98%ed%95%99ii-2k7-%ea%b0%80%ec%9d%84%ed%95%99%ea%b8%b0\/","title":{"rendered":"\ubbf8\ubd84\uae30\ud558\ud559II 2K7 \uac00\uc744\ud559\uae30"},"content":{"rendered":"<p> (TableOfContents) <\/p>\n<div id=\"outline-container-org5fbe15e\" class=\"outline-2\">\n<h2 id=\"org5fbe15e\">\uacf5\uc9c0<\/h2>\n<div class=\"outline-text-2\" id=\"text-org5fbe15e\">\n<ul class=\"org-ul\">\n<li>\uae30\ub9d0\uc2dc\ud5d8 \ucc44\uc810 \uacb0\uacfc\ub124\uc694. (160024:0.5\uc810, 160009:6&#x2014;\uc810, 160145:1-\uc810, 160002:5.5\uc810, 160011:4.5\uc810, 950168:3.5\uc810, 160135:3\uc810, 160085:1.5\uc810, 741002:0\uc810) \uc131\uc801\uc740 \uc2dc\ud5d8 \uc548 \ubcf8 \uc0ac\ub78c\ub4e4\ub3c4 \uc788\uc5b4\uc11c \ubcf8 \uc0ac\ub78c\ub4e4\uc740 \ubaa8\ub450 pass\ud560 \uac83 \uac19\uad70\uc694. \ud55c \ud559\uae30 \ub3d9\uc548 \uace0\uc0dd \ub9ce\uc774 \ud588\uc5b4\uc694. \uadf8\ub798\ub3c4 \uace0\uc0dd\ud55c \ubcf4\ub78c\uc774 \uc788\uc5c8\uc73c\uba74 \uc88b\uaca0\uc5b4\uc694.<\/li>\n<li>(12\/4) \uc774\uc81c\uc11c\uc57c \uc911\uac04\uc2dc\ud5d8 \ucc44\uc810\uc744 \ud588\ub124\uc694. \uc131\uc801\uc744 \uc801\uc5b4\ub461\ub2c8\ub2e4. \ud55c \ubb38\uc81c\ub2f9 1\uc810\uc529\uc73c\ub85c \ucc44\uc810\ud588\uc5b4\uc694.   (7\uc810:160002, 6\uc810:160011, 5.5\uc810:160009, 4.5\uc810:160085,160135,950168, 2.5\uc810:160024) \uc785\ub2c8\ub2e4.<\/li>\n<li>(10\/7) 1\ud559\uae30 \uc774\uc57c\uae30\uae4c\uc9c0 \ub2e4 \ud558\ub290\ub77c \uc9c4\ub3c4\uac00 \uc870\uae08 \ub2a6\uad70\uc694. \uc774\uc81c \ud55c 3\uc8fc \ub3d9\uc548 \uc870\uae08 \ube68\ub9ac \ub098\uac08\uac81\ub2c8\ub2e4. \ubbf8\ub9ac \ubb34\uc2a8 \uc774\uc57c\uae30\uac00 \uc788\ub294\uc9c0 \uc77d\uc5b4\ubcf4\uace0 \uc624\uc138\uc694. motivation\uc740 \uc870\uae08 \uc0dd\ub7b5\ud560\uaed8\uc694.<\/li>\n<li>\uc544\ub798 \uacf5\uc9c0 \uc774\ud6c4\uc5d0 \ub450 \uc0ac\ub78c\uc774 \uc774\ub984\uc744 \uc801\uc5c8\uc9c0\ub9cc \uc0ac\uc2e4 \uadf8 \uc774\uc804\uc5d0 \uc774\ubbf8 \uac15\uc758\ub85d\uc744 \uc8fc\ubb38\ud558\uc5ec\uc11c 2\ud559\uae30 \uac15\uc758\ub85d\ub9cc\uc774 \ub098\uc654\uc2b5\ub2c8\ub2e4. \uc218\ud559\uacfc \uc0ac\ubb34\uc2e4\uc5d0\uc11c \ubcf5\uc0ac\/\uc81c\ubcf8\ube44\ub97c \ub0b4\uace0 \ubc1b\uc544\uac00\uc138\uc694. 1\ud559\uae30 \ubd80\ubd84\uc744 \uc6d0\ud558\ub294 \uc0ac\ub78c\uc740 \ub2e4\uc2dc \ub0b4\uac8c \ub9d0\ud574\uc8fc\uc138\uc694.<\/li>\n<li>(9\/4) \uac15\uc758\ub85d\uc740 2\ud559\uae30 \uac15\uc758\ub85d\ub9cc\uc744 \uc81c\ubcf8\ud560\uae4c \ud558\uace0 \uc788\uc2b5\ub2c8\ub2e4. \uadf8\ub807\uc9c0\ub9cc \ud639\uc2dc \uc591\uc131\ub355\uad50\uc218\ub2d8\uc758 1\ud559\uae30 \uac15\uc758\ub85d\ub3c4 \ud55c\uaebc\ubc88\uc5d0 \uc81c\ubcf8\ud558\uae30\ub97c \uc6d0\ud558\ub294 \uc0ac\ub78c\uc740 \ub0b4\uac8c e-mail\ud558\ub358\uac00 \uc544\ub2c8\uba74 \uc5ec\uae30\uc5d0 \uc774\ub984\uc744 \ub0a8\uaca8\uc8fc\uc138\uc694. (\ucc38\uace0\ub85c \uc591\uad50\uc218\ub2d8\uc758 1\ud559\uae30 \uac15\uc758\ub85d\uc758 \uc624\ud0c0\uc640 \ub0b4\uc6a9\uc744 \ub9ce\uc774 \uace0\ucce4\uace0 \uadf8\ub9bc\ub3c4 \uc0c8\ub85c \ub4e4\uc5b4\uac04 \uac83\uc774 \ub9ce\uc2b5\ub2c8\ub2e4.)<\/li>\n<\/ul>\n<p> Xun Jiang(exchange student) <\/p>\n<\/div>\n<\/div>\n<div id=\"outline-container-org0cecba3\" class=\"outline-2\">\n<h2 id=\"org0cecba3\">\uc219\uc81c<\/h2>\n<div class=\"outline-text-2\" id=\"text-org0cecba3\">\n<ul class=\"org-ul\">\n<li>\uc219\uc81c \ubb38\uc81c\uc5d0 \ud78c\ud2b8\ub97c \ucd94\uac00\ud558\uace0 \ud2c0\ub9b0 \uae00\uc790\ub97c \ubc14\ub85c\uc7a1\uace0, \ud480\uc774\ub3c4 \ub2ec\uc558\uc2b5\ub2c8\ub2e4: <a href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-content\/uploads\/sites\/8\/attachments\/DiffGeometry2k7Fall\/2k7_dg_mid_hw_sol.pdf\">2k7_dg_mid_hw_sol.pdf<\/a><\/li>\n<li>(10\/18) \uc219\uc81c \ud30c\uc77c \ud558\ub098 \uc62c\ub77c\uac11\ub2c8\ub2e4. \uc774 \ubb38\uc81c\ub4e4\ub3c4 \ud480\uc5b4\ubcf4\uc138\uc694. \uacc4\uc0b0\uc744 \ubaa8\ub450 \uac80\ud1a0\ud558\uc9c0 \ubabb\ud588\uae30 \ub54c\ubb38\uc5d0 \uc55e\uc758 \ubb38\uc81c\ub294 \uacc4\uc0b0\uc774 \uc774\uc0c1\ud558\uba74 \ub0b4\uac8c \uc54c\ub824\uc8fc\uc138\uc694. <a href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-content\/uploads\/sites\/8\/attachments\/DiffGeometry2k7Fall\/2k7_dg_mid_hw.pdf\">2k7_dg_mid_hw.pdf<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div id=\"outline-container-orgc731c80\" class=\"outline-2\">\n<h2 id=\"orgc731c80\">\uac15\uc758 \uc790\ub8cc<\/h2>\n<div class=\"outline-text-2\" id=\"text-orgc731c80\">\n<p> 10\uc6d4 8\uc77c \uac15\uc758\ub85d: <a href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-content\/uploads\/sites\/8\/attachments\/DiffGeometry2k7Fall\/dg2k7_ln_05_egregium.pdf\">dg2k7_ln_05_egregium.pdf<\/a> , <a href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-content\/uploads\/sites\/8\/attachments\/DiffGeometry2k7Fall\/dg2k7_ln_06_geodesic.pdf\">dg2k7_ln_06_geodesic.pdf<\/a> <\/p>\n<p> \uad6c\uba74\uc0bc\uac01\ubc95: <a href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-content\/uploads\/sites\/8\/attachments\/DiffGeometry2k7Fall\/mm03_sph_trig.pdf\">mm03_sph_trig.pdf<\/a> <\/p>\n<\/div>\n<\/div>\n<div id=\"outline-container-orgc85eaf8\" class=\"outline-2\">\n<h2 id=\"orgc85eaf8\">\uc9c8\ubb38\ud558\uc138\uc694 Q&amp;A<\/h2>\n<div class=\"outline-text-2\" id=\"text-orgc85eaf8\">\n<p> Q: <\/p>\n<hr \/>\n<p> Q: \uad50\uc218\ub2d8, \uac15\uc758\ub85d page120, \uc815\ub9ac 3.2\uc758 \uc99d\uba85(K\ub294 \ub0b4\uc7ac\uc801 \uc591\uc774\ub2e4)\uc5d0 \u0393\uacfc L \uc774 \ub098\uc624\ub294\ub370 \uc774\uac83\ub4e4\uc774 \uc2dd\uc5d0\uc11c \ubb34\uc5c7\uc744 \uc758\ubbf8\ud558\ub294 \uac83\uc785\ub2c8\uae4c? <\/p>\n<ul class=\"org-ul\">\n<li>\n<p> 04\uc218\ud559\uacfc \uc774\ub3d9\uc120 <\/p>\n<p> A: \uc2dc\uac04\uc5d0 \uc124\uba85\ud588\uc9c0\uc694? \uc774\uac83\ub4e4\uc740 $ X_{ij} $ \ub97c basis\uc758 \uc77c\ucc28\uacb0\ud569\uc73c\ub85c \ub098\ud0c0\ub0b4\ub824\uace0 \ud560 \ub54c\uc758 \uacc4\uc218\ub85c \uc815\uc758\ub429\ub2c8\ub2e4. \uc989 \uc774 basis\uc5d0 \ub300\ud55c \uc131\ubd84 \ub610\ub294 \uc88c\ud45c\uc774\uc9c0\uc694. \uc774 \uc2dd\uc774 Gauss\uc758 \uacf5\uc2dd\uc785\ub2c8\ub2e4. <\/p>\n<\/li>\n<\/ul>\n<hr \/>\n<p> Q: \ubbf8\ubd84\uae30\ud558 \uac15\uc758\ub85d103page (5.3) $ &lt; e_1,e_2 &gt; &lt; e_2,e_2 &gt; &#8211; &lt; e_1,e_2 &gt; &lt; e_2,e_1 &gt; &gt; 0 $ \uc774 (1),(2)\uc5d0\uc11c \ub098\uc654\ub2e4\uace0 \ud558\ub294\ub370 \uc774\ud574\uac00 \uc548\uac11\ub2c8\ub2e4. \uc5b4\ub5bb\uac8c \ud55c\uac70\uc8e0? (\ud78c\ud2b8\ub77c\ub3c4 \uc0b4\uc9dd..) <\/p>\n<ul class=\"org-ul\">\n<li>04\uc218\ud559\uacfc \uc774\ub3d9\uc120<\/li>\n<\/ul>\n<p> A: \uc774\uac83\uc740 \uadf8\ub0e5 \ud55c \uc904\ub85c \ub098\uc624\ub294 \uadf8\ub7f0 \uac83\uc740 \uc544\ub2d9\ub2c8\ub2e4. \uc5b4\ub824\uc6b4 \uc774\ub860\uc744 \uc368\uc11c \uc81c\uc77c \uc27d\uac8c \uc54c \uc218 \uc788\ub294 \ubc29\ubc95\uc758 \ud558\ub098\ub294 \ub2e4\uc74c\uacfc \uac19\uc774 \uc0dd\uac01\ud558\ub294 \uac81\ub2c8\ub2e4: \uc6b0\uc120 \ucc45\uc758 \uac19\uc740 page\uc758 (5.2)\uc758 \ud589\ub82c\uc774 \ub300\uce6d\ud589\ub82c\uc774\ubbc0\ub85c \ub2e8\uc704\uace0\uc720\ubca1\ud130\ub97c basis\ub85c \uc368\uc11c \ub300\uac01\ud654\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uadf8\ub9ac\uace0 \ub098\uba74 \ub450 \uac1c\uc758 \uace0\uc720\uac12\uc740 \uc591\uc218\uac00 \ub3fc\uc57c \ud569\ub2c8\ub2e4.(\uc65c\ub0d0\ud558\uba74 \uadf8 \uace0\uc720\ubca1\ud130 $ v $ \ub97c $ &lt; v,v &gt; $ \ud560 \ub54c \uace0\uc720\uac12\uc774 \uacf1\ud574\uc9c0\ub2c8\uae4c\uc694.) \uadf8\ub7f0\ub370 (5.3)\uc758 \ud589\ub82c\uc2dd\uc758 \uac12\uc740 \uc0c8 basis\uc5d0 \ub300\ud558\uc5ec \uc368\ub3c4 \uac19\uc740 \uac12\uc774 \ub418\ub294\ub370, \uc774 \uc0c8 \ud589\ub82c\uc758 \ud589\ub82c\uc2dd\uc740 \ub450 \uace0\uc720\uac12\uc758 \uacf1\uc774 \ub418\uc9c0\uc694. \ubb3c\ub860 \uc591\uc218\uc774\uace0\uc694. \uc774\ubcf4\ub2e4 \uc870\uae08 \uac04\ub2e8\ud558\uac8c \uacc4\uc0b0\ud558\ub294 \ubc29\ubc95\uc740 \uc774 \ud589\ub82c\uc744 \uc644\uc804\uc81c\uacf1\uc73c\ub85c \ubc14\uafb8\ub294 \uac83\uc785\ub2c8\ub2e4. \uadf8\ub7f0\ub370 \uc9c1\uad50\ubcc0\ud658\uc744 \ud558\uc9c0 \uc54a\uace0 \ub2e4\uc74c\uacfc \uac19\uc774 \ud558\ub294 \uac70\uc9c0\uc694. (\uc5b4\ub824\uc6b4 \uc774\ub860\uc744 \uc548 \uc4f0\ub294 \ub300\uc2e0 \uc774\uac83\uc740 \uc124\uba85\uc774 \uc5c6\ub294 \uadf8\ub0e5 \uacc4\uc0b0\uc785\ub2c8\ub2e4.) \\[  = ax^2+ 2bxy+cy^2=a(x+ \\frac{b}{a} y)^2 + \\frac{1}{a} (-b^2+ac) y^2 \\] \uc774\ub2c8\uae4c \ubaa8\ub4e0 $ (x,y) $ \uc5d0 \ub300\ud558\uc5ec \uc704\uc758 \uc2dd\uc774 \uc591\uc218\uac00 \ub418\ub824\uba74 $ a&gt;0 $ \uc774\uace0 $ ac-b^2&gt;0 $ \uc774\ub77c\uc57c \ud558\uaca0\uc9c0\uc694? \uc774\uac74 \ud55c \uc904\ub85c \ub098\uc654\ub124\uc694. \ud558\uc9c0\ub9cc $ n&times; n $ \ud589\ub82c\uc5d0 \ub300\ud558\uc5ec \uc99d\uba85\ud558\ub824\uba74 \uacc4\uc0b0\uc774 \uc870\uae08 \uae38\uc9c0\uc694. \uadf8\ub9ac\uace0 \uc65c \uaf2d \ud589\ub82c\uc2dd\uc774\ub77c\uc57c \ud558\ub294\uc9c0 \uc124\uba85\uc774 \uc5b4\ub835\uace0\uc694. &#8211; \uae40\uc601\uc6b1 <\/p>\n<p> Q: \uad50\uc218\ub2d8 \uac10\uc0ac\ud569\ub2c8\ub2e4. \uc55e\ubd80\ubd84 \uc124\uba85\uc740 \uc798\uc774\ud574\ud558\uc9c0 \ubabb\ud558\uaca0\uc73c\ub098 \uc544\ub798 \uc2dd\uc744 \ubcf4\ub2c8 \uc774\ud574\uac00 \uac11\ub2c8\ub2e4. \ud558\uc9c0\ub9cc \\[ \\frac{1}{a} (b^2-ac) y^2 \\]  \uc758 \ubd80\ud638\uac00 \ubc18\ub300\ub85c \uc801\ud600 \uc788\uc2b5\ub2c8\ub2e4. <\/p>\n<ul class=\"org-ul\">\n<li>04\uc218\ud559\uacfc \uc774\ub3d9\uc120 A: \uc544 \ub9de\uc544\uc694.<\/li>\n<\/ul>\n<hr \/>\n<p> CategoryKUMath <\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>(TableOfContents) \uacf5\uc9c0 \uae30\ub9d0\uc2dc\ud5d8 \ucc44\uc810 \uacb0\uacfc\ub124\uc694. (160024:0.5\uc810, 160009:6&#x2014;\uc810, 160145:1-\uc810, 160002:5.5\uc810, 160011:4.5\uc810, 950168:3.5\uc810, 160135:3\uc810, 160085:1.5\uc810, 741002:0\uc810) \uc131\uc801\uc740 \uc2dc\ud5d8 \uc548 \ubcf8 \uc0ac\ub78c\ub4e4\ub3c4 \uc788\uc5b4\uc11c \ubcf8 \uc0ac\ub78c\ub4e4\uc740 \ubaa8\ub450 pass\ud560 \uac83 \uac19\uad70\uc694. \ud55c \ud559\uae30 \ub3d9\uc548 \uace0\uc0dd \ub9ce\uc774 \ud588\uc5b4\uc694. \uadf8\ub798\ub3c4 \uace0\uc0dd\ud55c \ubcf4\ub78c\uc774 \uc788\uc5c8\uc73c\uba74 \uc88b\uaca0\uc5b4\uc694. (12\/4) \uc774\uc81c\uc11c\uc57c \uc911\uac04\uc2dc\ud5d8 \ucc44\uc810\uc744 \ud588\ub124\uc694. \uc131\uc801\uc744 \uc801\uc5b4\ub461\ub2c8\ub2e4. \ud55c \ubb38\uc81c\ub2f9 1\uc810\uc529\uc73c\ub85c \ucc44\uc810\ud588\uc5b4\uc694. (7\uc810:160002, 6\uc810:160011, 5.5\uc810:160009, 4.5\uc810:160085,160135,950168, 2.5\uc810:160024) \uc785\ub2c8\ub2e4. (10\/7) &#8230; <a title=\"\ubbf8\ubd84\uae30\ud558\ud559II 2K7 \uac00\uc744\ud559\uae30\" class=\"read-more\" href=\"https:\/\/mathematicians.korea.ac.kr\/ywkim\/2008\/08\/26\/%eb%af%b8%eb%b6%84%ea%b8%b0%ed%95%98%ed%95%99ii-2k7-%ea%b0%80%ec%9d%84%ed%95%99%ea%b8%b0\/\" aria-label=\"\ubbf8\ubd84\uae30\ud558\ud559II 2K7 \uac00\uc744\ud559\uae30\uc5d0 \ub300\ud574 \ub354 \uc790\uc138\ud788 \uc54c\uc544\ubcf4\uc138\uc694\">\ub354 \uc77d\uae30<\/a><\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[11],"tags":[],"class_list":["post-3354","post","type-post","status-publish","format-standard","hentry","category-lectures"],"distributor_meta":false,"distributor_terms":false,"distributor_media":false,"distributor_original_site_name":"\uae40\uc601\uc6b1","distributor_original_site_url":"https:\/\/mathematicians.korea.ac.kr\/ywkim","push-errors":false,"_links":{"self":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts\/3354","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/comments?post=3354"}],"version-history":[{"count":1,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts\/3354\/revisions"}],"predecessor-version":[{"id":3355,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/posts\/3354\/revisions\/3355"}],"wp:attachment":[{"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/media?parent=3354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/categories?post=3354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mathematicians.korea.ac.kr\/ywkim\/wp-json\/wp\/v2\/tags?post=3354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}