{"id":6701,"date":"2021-07-20T23:59:16","date_gmt":"2021-07-20T14:59:16","guid":{"rendered":"https:\/\/sasamath.com\/blog\/?page_id=6701"},"modified":"2021-09-21T16:11:25","modified_gmt":"2021-09-21T07:11:25","slug":"continuity","status":"publish","type":"page","link":"https:\/\/sasamath.com\/blog\/invitation-to-calculus\/continuity\/","title":{"rendered":"\uc5f0\uc18d\uc758 \uc815\uc758"},"content":{"rendered":"<style type=\"text\/css\">\n\timg.mfp-img { background-color: white; }\n<\/style>\n<div class=\"box itc_intro\">\n<p>\uc774 \uae00\uc740 \u300e\ubbf8\uc801\ubd84\ud559 \uccab\uac78\uc74c\u300f 4\uc7a5 1\uc808\uc758 \ub0b4\uc6a9\uc785\ub2c8\ub2e4.&nbsp; <span class=\"itc_viewcontents\">(<a href=\"..\/\">\ubbf8\uc801\ubd84\ud559 \uccab\uac78\uc74c \ucc28\ub840 \ubcf4\uae30<\/a>)<\/span><\/p>\n<\/div>\n<p>\ud568\uc218 \\(f:D \\rightarrow \\mathbb{R}\\)\uac00 \uc8fc\uc5b4\uc838 \uc788\uace0, \\(c\\)\uac00 \\(D\\)\uc758 \uc810\uc774\ub77c\uace0 \ud558\uc790. \ub9cc\uc57d \ub2e4\uc74c \ub450 \uac00\uc9c0 \uc911 \ud558\ub098\uac00 \uc131\ub9bd\ud558\uba74 \u201c\\(f\\)\uac00 \\(c\\)\uc5d0\uc11c  <span class=\"defined\">\uc5f0\uc18d\uc774\ub2e4<\/span>(continuous)\u201d\ub77c\uace0 \ub9d0\ud55c\ub2e4.<\/p>\n<ul>\n<li>\\(c\\)\uac00 \\(D\\)\uc758 \uc9d1\uc801\uc810\uc774\uace0 \\(\\displaystyle\\lim_{x\\rightarrow c} f(x)=f(c)\\)\uc774\ub2e4.<\/li>\n<li>\\(c\\)\uac00 \\(D\\)\uc758 \uc9d1\uc801\uc810\uc774 \uc544\ub2c8\ub2e4.<\/li>\n<\/ul>\n<p>\\(c\\)\uac00 \\(f\\)\uc758 \uc815\uc758\uc5ed\uc758 \uc810\uc774\uace0 \\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \uc544\ub2c8\uba74 \u201c\\(f\\)\uac00 \\(c\\)\uc5d0\uc11c <span class=\"defined\">\ubd88\uc5f0\uc18d\uc774\ub2e4<\/span>(discontinuous)\u201d\ub77c\uace0 \ub9d0\ud55c\ub2e4.<\/p>\n<p>\ud568\uc218 \\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \ubd88\uc5f0\uc18d\uc774\uc9c0\ub9cc \\(c\\)\uc5d0\uc11c \\(f\\)\uc758 \uc88c\uadf9\ud55c\uacfc \uc6b0\uadf9\ud55c\uc774 \ubaa8\ub450 \uc874\uc7ac\ud558\uba74, \u201c\\(f\\)\uac00 \\(c\\)\uc5d0\uc11c <span class=\"defined\">\ub2e8\uc21c\ubd88\uc5f0\uc18d\uc774\ub2e4<\/span>\u201d\ub77c\uace0 \ub9d0\ud55c\ub2e4(simple discontinuity). \ud568\uc218 \\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \ubd88\uc5f0\uc18d\uc774\uace0 \\(c\\)\uac00 \\(f\\)\uc758 \ub2e8\uc21c\ubd88\uc5f0\uc18d\uc810\uc774 \uc544\ub2c8\uba74, \\(c\\)\ub97c \\(f\\)\uc758 <span class=\"defined\">\uc81c 2 \uc885 \ubd88\uc5f0\uc18d\uc810<\/span>\uc774\ub77c\uace0 \ubd80\ub978\ub2e4(second kind discontinuity).<\/p>\n<p>\ud568\uc218 \\(f\\)\uac00 \uc815\uc758\uc5ed\uc758 \ubaa8\ub4e0 \uc810\uc5d0\uc11c \uc5f0\uc18d\uc774\uba74 \\(f\\)\ub97c <span class=\"defined\">\uc5f0\uc18d\ud568\uc218<\/span>(continuous function)\ub77c\uace0 \ubd80\ub978\ub2e4.<\/p>\n<p>\uc810 \\(c\\)\uac00 \ud568\uc218 \\(f\\)\uc758 \uc815\uc758\uc5ed\uc758 \uc9d1\uc801\uc810\uc774\ub77c\uace0 \ud558\uc790. \uadf8\ub7ec\uba74 \\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc778\uc9c0 \ud310\ubcc4\ud558\uae30 \uc704\ud574\uc11c\ub294 \ub2e4\uc74c \uc138 \uc870\uac74\uc774 <span class=\"defined\">\ubaa8\ub450<\/span> \ub9cc\uc871\ub418\ub294\uc9c0\ub97c \uc0b4\ud53c\uba74 \ub41c\ub2e4.<\/p>\n<ul>\n<li>\\(f(c)\\)\uac00 \uc815\uc758\ub41c\ub2e4. &nbsp;(\\(c\\)\uc5d0\uc11c \\(f\\)\uc758 \ud568\uc22b\uac12\uc774 \uc874\uc7ac\ud55c\ub2e4.)<\/li>\n<li>\\(\\displaystyle\\lim_{x\\rightarrow c}f(x)\\)\uac00 \uc874\uc7ac\ud55c\ub2e4. &nbsp;(\\(c\\)\uc5d0\uc11c \\(f\\)\uc758 \uadf9\ud55c\uc774 \uc218\ub834\ud55c\ub2e4.)<\/li>\n<li>\\(\\displaystyle\\lim_{x\\rightarrow c}f(x) = f(c).\\) &nbsp;(\\(c\\)\uc5d0\uc11c \\(f\\)\uc758 \uadf9\ud55c\uac12\uacfc \ud568\uc22b\uac12\uc774 \uc77c\uce58\ud55c\ub2e4.<\/li>\n<\/ul>\n<p>\ud568\uc218 \\(f,\\) \\(g,\\) \\(h\\)\uc758 \uadf8\ub798\ud504\uac00 \uc544\ub798 \uadf8\ub9bc\uacfc \uac19\uc744 \ub54c, \ud568\uc218 \\(f\\)\ub294 \uc810 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\uace0 \ud568\uc218 \\(g\\)\uc640 \\(h\\)\ub294 \uc810 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \uc544\ub2c8\ub2e4.<\/p>\n<div>\n<a href=\"\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123.png\" data-rel=\"penci-gallery-image-content\" ><img fetchpriority=\"high\" decoding=\"async\" src=\"\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123.png\" alt=\"\" width=\"599\" height=\"183\" class=\"aligncenter size-full wp-image-7784\" srcset=\"https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123.png 1798w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123-300x92.png 300w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123-1024x313.png 1024w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123-768x235.png 768w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123-1536x470.png 1536w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123-1170x358.png 1170w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_123-585x179.png 585w\" sizes=\"(max-width: 599px) 100vw, 599px\" \/><\/a>\n<\/div>\n<div class=\"example\">\n<p><span class=\"example\">\ubcf4\uae30 4.1.1.<\/span><\/p>\n<ol class=\"parenthesis\">\n<li>\ud568\uc218 \\(f\\)\uac00 \\(f(x)=x^2\\)\uc73c\ub85c \uc8fc\uc5b4\uc84c\ub2e4\uace0 \ud558\uc790. \uadf8\ub7ec\uba74 \\(f\\)\ub294 \\(\\mathbb{R}\\)\uc5d0\uc11c \uc5f0\uc18d\uc778 \ud568\uc218\uc774\ub2e4 \uc65c\ub0d0\ud558\uba74 \\(\\mathbb{R}\\)\uc758 \ubaa8\ub4e0 \uc810\uc5d0\uc11c \\(f\\)\uc758 \uadf9\ud55c\uac12\uacfc \ud568\uc22b\uac12\uc774 \uc77c\uce58\ud558\uae30 \ub54c\ubb38\uc774\ub2e4.<\/li>\n<li>\ud568\uc218 \\(g\\)\uac00\\[g(x)=\\frac{x^2 -x-6}{x-3}\\]\uc73c\ub85c \uc8fc\uc5b4\uc84c\ub2e4\uace0 \ud558\uc790. \uadf8\ub7ec\uba74 \\(g\\)\ub294 \\(3\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \uc544\ub2c8\ub2e4. \uc65c\ub0d0\ud558\uba74 \\(3\\)\uc740 \\(g\\)\uc758 \uc815\uc758\uc5ed\uc758 \uc6d0\uc18c\uac00 \uc544\ub2c8\uae30 \ub54c\ubb38\uc774\ub2e4. \\(g\\)\ub294 \\(3\\)\uc744 \uc81c\uc678\ud55c \ubaa8\ub4e0 \uc810\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\ud568\uc218 \\(h\\)\uac00 \\[h(x) = \\lfloor x \\rfloor\\]\ub85c \uc8fc\uc5b4\uc84c\ub2e4\uace0 \ud558\uc790. \uc989 \\(h\\)\uac00 \ucd5c\ub300\uc815\uc218\ud568\uc218\ub77c\uace0 \ud558\uc790. \ub9cc\uc57d \\(n\\)\uc774 \uc815\uc218\uc774\uba74 \\(h\\)\ub294 \\(n\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \uc544\ub2c8\ub2e4. \uc65c\ub0d0\ud558\uba74 \\(n\\)\uc5d0\uc11c \\(h\\)\uc758 \uadf9\ud55c\uc774 \uc218\ub834\ud558\uc9c0 \uc54a\uae30 \ub54c\ubb38\uc774\ub2e4. \ud558\uc9c0\ub9cc \\(n\\)\uc5d0\uc11c \\(h\\)\uc758 \uc88c\uadf9\ud55c\uacfc \uc6b0\uadf9\ud55c\uc774 \ubaa8\ub450 \uc874\uc7ac\ud558\ubbc0\ub85c \\(h\\)\ub294 \\(n\\)\uc5d0\uc11c \ub2e8\uc21c\ubd88\uc5f0\uc18d\uc774\ub2e4. \ub9cc\uc57d \\(c\\)\uac00 \uc815\uc218\uac00 \uc544\ub2cc \uc2e4\uc218\ub77c\uba74 \\(h\\)\ub294 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\ud568\uc218 \\(f\\)\uac00 \\(\\mathbb{Z}\\)\uc5d0\uc11c \uc815\uc758\ub418\uc5c8\ub2e4\uba74 \\(f\\)\ub294 \\(\\mathbb{Z}\\)\uc758 \ubaa8\ub4e0 \uc810\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4. \uc65c\ub0d0\ud558\uba74 \\(\\mathbb{Z}\\)\uc758 \uc784\uc758\uc758 \uc810\uc740 \\(\\mathbb{Z}\\)\uc758 \uc9d1\uc801\uc810\uc774 \uc544\ub2c8\uae30 \ub54c\ubb38\uc774\ub2e4.<\/li>\n<li>\ud568\uc218 \\(g\\)\uac00 \\(g(x)=\\chi_\\mathbb{Q} (x)\\)\ub85c \uc815\uc758\ub418\uc5c8\ub2e4\uba74 \\(g\\)\ub294 \uc5b4\ub290 \uc810\uc5d0\uc11c\ub3c4 \uc5f0\uc18d\uc774 \uc544\ub2c8\ub2e4. \\(g\\)\ub294 \uc784\uc758\uc758 \uc810\uc5d0\uc11c \uc81c 2 \uc885 \ubd88\uc5f0\uc18d\uc774\ub2e4.<\/li>\n<\/ol>\n<\/div>\n<p>\ud568\uc218\uc758 \uadf9\ud55c\uc758 \uc131\uc9c8\ub85c\ubd80\ud130 \ub2e4\uc74c \uc815\ub9ac\ub97c \uc5bb\ub294\ub2e4.<\/p>\n<div class=\"theorem margintop2\">\n<p><span class=\"theorem\">\uc815\ub9ac 4.1.1.<\/span><\/p>\n<p>\ub450 \ud568\uc218 \\(f\\)\uc640 \\(g\\)\uac00 \uac19\uc740 \uc815\uc758\uc5ed\uc744 \uac16\ub294 \ud568\uc218\ub77c\uace0 \ud558\uc790. \ub9cc\uc57d \\(f\\)\uc640 \\(g\\)\uac00 \ubaa8\ub450 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\uba74 \ub2e4\uc74c\uc774 \uc131\ub9bd\ud55c\ub2e4.<\/p>\n<ol class=\"bracket\">\n<li>\\(f+g\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\\(f-g\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\\(k\\)\uac00 \uc0c1\uc218\uc774\uba74 \\(kf\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\\(g(c) \\ne 0\\)\uc774\uba74 \\(f\/g\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\\(m\\)\uc774 \uc591\uc758 \uc815\uc218\uc774\uace0 \\(f\\ge 0\\)\uc774\uba74 \\(\\sqrt[m]{f}\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<\/ol>\n<\/div>\n<div class=\"example\">\n<p><span class=\"example\">\ubcf4\uae30 4.1.2.<\/span><\/p>\n<ol class=\"parenthesis\">\n<li>\ubaa8\ub4e0 \ub2e4\ud56d\ud568\uc218\ub294 \\(\\mathbb{R}\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\\(p(x)\\)\uc640 \\(q(x)\\)\uac00 \ub2e4\ud56d\uc2dd\uc774\uba74<br \/>\n\\[f(x) = \\frac{p(x)}{q(x)}\\]<br \/>\n\ub85c \uc815\uc758\ub41c \uc720\ub9ac\ud568\uc218 \\(f\\)\ub294 \\(q(x)=0\\)\uc758 \uadfc\uc744 \uc81c\uc678\ud55c \uc810\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<\/ol>\n<\/div>\n<div class=\"example\">\n<p><span class=\"example\">\uc608\uc81c 4.1.3.<\/span><br \/>\n\\(a\\)\uc640 \\(b\\)\uac00 \uc0c1\uc218\uc774\uace0 \ud568\uc218 \\(f:\\mathbb{R} \\rightarrow \\mathbb{R}\\)\uac00 \ub2e4\uc74c\uacfc \uac19\uc774 \uc8fc\uc5b4\uc84c\ub2e4.<br \/>\n\\[f(x) = \\begin{cases} \\displaystyle \\frac{x^2 -2x +a}{x-1} &#038; \\quad \\text{if}\\,\\, x\\ne 1 \\\\ b+1 &#038; \\quad \\text{if}\\,\\, x=1 \\end{cases}\\]<br \/>\n\uc774\ub54c \\(f\\)\uac00 \\(\\mathbb{R}\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \ub418\ub3c4\ub85d \ud558\ub294 \\(a\\)\uc640 \\(b\\)\uc758 \uac12\uc744 \uac01\uac01 \uad6c\ud558\uc2dc\uc624.<\/p>\n<p class=\"margintop1\"><span class=\"proof\">\ud480\uc774.<\/span> \\(f\\)\uac00 \\(1\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ubbc0\ub85c<br \/>\n\\[\\lim_{x\\rightarrow 1}f(x) = f(1)\\]<br \/>\n\uc989<br \/>\n\\[\\lim_{x\\rightarrow 1} \\frac{x^2 -2x+a}{x-1} =b+1\\tag{a}\\]<br \/>\n\uc774\ub2e4. \\(x\\rightarrow 1\\)\uc77c \ub54c \uc704 \ub4f1\uc2dd\uc758 \uc88c\ubcc0\uc758 \ubd84\ubaa8\uac00 \\(0\\)\uc5d0 \uc218\ub834\ud558\ubbc0\ub85c \ubd84\uc790\ub3c4 \\(0\\)\uc5d0 \uc218\ub834\ud574\uc57c \ud55c\ub2e4. \uadf8\ub7ec\ubbc0\ub85c<br \/>\n\\[\\lim_{x\\rightarrow 1} \\left(x^2 -2x+a \\right) = a-1 =0\\]<br \/>\n\uc989 \\(a=1\\)\uc774\ub2e4. \uc774 \uac12\uc744 (a)\uc5d0 \ub300\uc785\ud558\uba74<br \/>\n\\[\\lim_{x\\rightarrow 1} \\frac{x^2 -2x+1}{x-1} = b+1\\]<br \/>\n\uc774\ub2e4. \uc774 \uc2dd\uc744 \ud480\uba74<br \/>\n\\[0 = b+1\\]<br \/>\n\uc774\ubbc0\ub85c \\(b=-1\\)\uc774\ub2e4.\n<\/p>\n<\/div>\n<p>\\(I = [a,\\,b]\\)\uac00 \uae38\uc774\uac00 \uc591\uc218\uc778 \ub2eb\ud788 \uad6c\uac04\uc774\uace0 \\(f\\)\uac00 \\(I\\)\uc5d0\uc11c \uc815\uc758\ub41c \ud568\uc218\ub77c\uace0 \ud558\uc790. \ub9cc\uc57d \\(f\\)\uac00 \ub2e4\uc74c \uc138 \uc870\uac74\uc744 \ubaa8\ub450 \ub9cc\uc871\uc2dc\ud0a4\uba74 \u201c\\(f\\)\uac00 <span class=\"defined\">\uad6c\uac04 \\(\\boldsymbol{I}\\)\uc5d0\uc11c \uc5f0\uc18d<\/span>\uc774\ub2e4\u201d\ub77c\uace0 \ub9d0\ud55c\ub2e4.<\/p>\n<ol class=\"bracket\">\n<li>\\(a < c < b\\)\uc778 \ubaa8\ub4e0 \uc810 \\(c\\)\uc5d0\uc11c \\(f\\)\uac00 \uc5f0\uc18d\uc774\ub2e4.<\/li>\n<li>\\(\\displaystyle \\lim_{x\\rightarrow a^+} f(x) = f(a)\\)\uc774\ub2e4. \uc989 \\(f\\)\uac00 \\(a\\)\uc5d0\uc11c <span class=\"defined\">\uc6b0\uc5f0\uc18d<\/span>\uc774\ub2e4. (continuous on the right at \\(a.\\))<\/li>\n<li>\\(\\displaystyle \\lim_{x\\rightarrow b^-} f(x) = f(b)\\)\uc774\ub2e4. \uc989 \\(f\\)\uac00 \\(b\\)\uc5d0\uc11c <span class=\"defined\">\uc88c\uc5f0\uc18d<\/span>\uc774\ub2e4. (continuous on the left at \\(b.\\))<\/li>\n<\/ol>\n<p>\uc704 \uc815\uc758\uc5d0\uc11c \ud568\uc218 \\(f\\)\uc758 \uc815\uc758\uc5ed \uc804\uccb4\ub97c \uace0\ub824\ud558\uba74 \\(f\\)\uac00 \\(a\\)\ub098 \\(b\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \uc544\ub2d0 \uc218 \uc788\ub2e4.<\/p>\n<div class=\"example\">\n<p><span class=\"example\">\ubcf4\uae30 4.1.4.<\/span><br \/>\n\ud568\uc218 \\(f\\)\uac00 \\(\\mathbb{R}\\)\uc5d0\uc11c \ub2e4\uc74c\uacfc \uac19\uc774 \uc815\uc758\ub418\uc5c8\ub2e4\uace0 \ud558\uc790.<br \/>\n\\[f(x) = \\begin{cases}<br \/>\n1 &#038; \\quad \\text{if} \\,\\, x < 1 \\\\[4pt]\n3 &#038; \\quad \\text{if} \\,\\, 1 \\le x \\le 3 \\\\[4pt]\n2 &#038; \\quad \\text{if} \\,\\, x > 3<br \/>\n\\end{cases}\\]<br \/>\n\uc774 \ud568\uc218\uc758 \uadf8\ub798\ud504\ub294 \uc544\ub798 \uadf8\ub9bc\uacfc \uac19\ub2e4.<\/p>\n<div>\n<a href=\"\/blog\/wp-content\/uploads\/2021\/09\/ic_401_4.png\" data-rel=\"penci-gallery-image-content\" ><img decoding=\"async\" src=\"\/blog\/wp-content\/uploads\/2021\/09\/ic_401_4.png\" alt=\"\" width=\"185\" height=\"144\" class=\"aligncenter size-full wp-image-7783\" srcset=\"https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_4.png 556w, https:\/\/sasamath.com\/blog\/wp-content\/uploads\/2021\/09\/ic_401_4-300x233.png 300w\" sizes=\"(max-width: 185px) 100vw, 185px\" \/><\/a>\n<\/div>\n<p>\ud568\uc218 \\(f\\)\ub294 \\(1\\)\uacfc \\(3\\)\uc5d0\uc11c \ubd88\uc5f0\uc18d\uc774\ub2e4. \uadf8\ub7fc\uc5d0\ub3c4 \ubd88\uad6c\ud558\uace0 \\(f\\)\ub294 \ub2eb\ud78c\uad6c\uac04 \\([1,\\,3]\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4.<\/p>\n<\/div>\n<p><!-- ##################################################################### --><br \/>\n<!--\n\n\n<h2 class=\"itc_h2\">\uc81c\ubaa9<\/h2>\n\n\n\n\n\n<p>.<\/p>\n\n\n\n\n\n<p>.<\/p>\n\n\n--><\/p>\n<p><!--\n\n\n\n<div class=\"theorem margintop2\">\n\n\n<p><span class=\"theorem\">\uc815\ub9ac 1.<\/span>\n\n\n<\/p>\n\n<\/div>\n\n\n\n\n\n<div class=\"proof\">\n\n\n<p class=\"proofname\">\uc99d\uba85.<\/p>\n\n\n\n\n<p>\n\n<span class=\"qed\"><\/span><\/p>\n\n<\/div>\n\n\n\n\n########\n\n\u201c\u201d\n\u2018\u2019\n\n\n\n<div class=\"example\">\n\n\n<p><span class=\"example\">\ubcf4\uae30 1.<\/span>\n\n<\/p>\n\n<\/div>\n\n\n\n\n\n<h2 class=\"itc_h2\"><\/h2>\n\n\n\n--><\/p>\n<p><!--\n\n\n<div style=\"display: none; visibility: hidden;\">\n\\[\n\\newcommand{\\Hom}{{\\operatorname{Hom}}}\n\\newcommand{\\Mat}{{\\operatorname{Mat}}}\n\\newcommand{\\proj}{{\\operatorname{proj}}}\n\\newcommand{\\adj}{{\\operatorname{adj}}}\n\\]\n<\/div>\n\n\n--><\/p>\n<div class=\"box itc_prev_next_box\">\n<ul class=\"itc_ul\">\n<li class=\"itc_li_prev\">\uc55e\uc758 \uae00 : <a href=\"..\/asymptotes\">\ud568\uc218\uc758 \uadf8\ub798\ud504\uc758 \uc810\uadfc\uc120<\/a><\/li>\n<li class=\"itc_li_next\">\ub2e4\uc74c \uae00 : <a href=\"..\/properties-of-continuous-functions\">\uc5f0\uc18d\ud568\uc218\uc758 \uc131\uc9c8<\/a><\/li>\n<\/ul>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\uc774 \uae00\uc740 \u300e\ubbf8\uc801\ubd84\ud559 \uccab\uac78\uc74c\u300f 4\uc7a5 1\uc808\uc758 \ub0b4\uc6a9\uc785\ub2c8\ub2e4.&nbsp; (\ubbf8\uc801\ubd84\ud559 \uccab\uac78\uc74c \ucc28\ub840 \ubcf4\uae30) \ud568\uc218 \\(f:D \\rightarrow \\mathbb{R}\\)\uac00 \uc8fc\uc5b4\uc838 \uc788\uace0, \\(c\\)\uac00 \\(D\\)\uc758 \uc810\uc774\ub77c\uace0 \ud558\uc790. \ub9cc\uc57d \ub2e4\uc74c \ub450 \uac00\uc9c0 \uc911 \ud558\ub098\uac00 \uc131\ub9bd\ud558\uba74 \u201c\\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774\ub2e4(continuous)\u201d\ub77c\uace0 \ub9d0\ud55c\ub2e4. \\(c\\)\uac00 \\(D\\)\uc758 \uc9d1\uc801\uc810\uc774\uace0 \\(\\displaystyle\\lim_{x\\rightarrow c} f(x)=f(c)\\)\uc774\ub2e4. \\(c\\)\uac00 \\(D\\)\uc758 \uc9d1\uc801\uc810\uc774 \uc544\ub2c8\ub2e4. \\(c\\)\uac00 \\(f\\)\uc758 \uc815\uc758\uc5ed\uc758 \uc810\uc774\uace0 \\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \uc5f0\uc18d\uc774 \uc544\ub2c8\uba74 \u201c\\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \ubd88\uc5f0\uc18d\uc774\ub2e4(discontinuous)\u201d\ub77c\uace0 \ub9d0\ud55c\ub2e4. \ud568\uc218 \\(f\\)\uac00 \\(c\\)\uc5d0\uc11c \ubd88\uc5f0\uc18d\uc774\uc9c0\ub9cc \\(c\\)\uc5d0\uc11c \\(f\\)\uc758 \uc88c\uadf9\ud55c\uacfc \uc6b0\uadf9\ud55c\uc774 \ubaa8\ub450 \uc874\uc7ac\ud558\uba74,&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":6620,"menu_order":401,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"class_list":["post-6701","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/pages\/6701","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/comments?post=6701"}],"version-history":[{"count":33,"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/pages\/6701\/revisions"}],"predecessor-version":[{"id":7852,"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/pages\/6701\/revisions\/7852"}],"up":[{"embeddable":true,"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/pages\/6620"}],"wp:attachment":[{"href":"https:\/\/sasamath.com\/blog\/wp-json\/wp\/v2\/media?parent=6701"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}