{"id":11826,"date":"2014-02-26T16:01:27","date_gmt":"2014-02-26T16:01:27","guid":{"rendered":"https:\/\/www.acasinhadamatematica.pt\/?p=11826"},"modified":"2021-12-26T15:57:09","modified_gmt":"2021-12-26T15:57:09","slug":"caracterize-as-funcoes","status":"publish","type":"post","link":"https:\/\/www.acasinhadamatematica.pt\/?p=11826","title":{"rendered":"Caracterize as fun\u00e7\u00f5es"},"content":{"rendered":"<p><ul id='GTTabs_ul_11826' class='GTTabs' style='display:none'>\n<li id='GTTabs_li_0_11826' class='GTTabs_curr'><a  id=\"11826_0\" onMouseOver=\"GTTabsShowLinks('Enunciado'); return true;\"  onMouseOut=\"GTTabsShowLinks();\"  class='GTTabsLinks'>Enunciado<\/a><\/li>\n<li id='GTTabs_li_1_11826' ><a  id=\"11826_1\" onMouseOver=\"GTTabsShowLinks('Resolu\u00e7\u00e3o'); return true;\"  onMouseOut=\"GTTabsShowLinks();\"  class='GTTabsLinks'>Resolu\u00e7\u00e3o<\/a><\/li>\n<\/ul>\n\n<div class='GTTabs_divs GTTabs_curr_div' id='GTTabs_0_11826'>\n<span class='GTTabs_titles'><b>Enunciado<\/b><\/span><\/p>\n<p>Considere as fun\u00e7\u00f5es definidas por:<\/p>\n<p>\u00a0\\[\\begin{array}{*{20}{l}}<br \/>\n{\\begin{array}{*{20}{l}}<br \/>\n{f:}&amp;{\\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{1}{{{x^2}}}}<br \/>\n\\end{array}}&amp;{}&amp;{}&amp;{\\begin{array}{*{20}{l}}<br \/>\n{g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to x + 1}<br \/>\n\\end{array}}&amp;{}&amp;{}&amp;{\\begin{array}{*{20}{l}}<br \/>\n{h:}&amp;{\\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{1}{{{x^2} &#8211; x}}}<br \/>\n\\end{array}}<br \/>\n\\end{array}\\]<\/p>\n<p>Caracterize as fun\u00e7\u00f5es seguintes:<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{f + g}&amp;{}&amp;{f \\times g}&amp;{}&amp;{\\frac{f}{g}}&amp;{}&amp;{h &#8211; g}&amp;{}&amp;{\\frac{f}{h}}&amp;{}&amp;{f \\circ g}&amp;{}&amp;{g \\circ f}<br \/>\n\\end{array}\\]<\/p>\n<p><div class='GTTabsNavigation' style='display:none'><span class='GTTabs_nav_next'><a href='#GTTabs_ul_11826' onClick='GTTabs_show(1,11826)'>Resolu\u00e7\u00e3o &gt;&gt;<\/a><\/span><\/div><\/div>\n\n<div class='GTTabs_divs' id='GTTabs_1_11826'>\n<span class='GTTabs_titles'><b>Resolu\u00e7\u00e3o<\/b><\/span><!--more--><\/p>\n<blockquote>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{\\begin{array}{*{20}{l}}<br \/>\n{f:}&amp;{\\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{1}{{{x^2}}}}<br \/>\n\\end{array}}&amp;{}&amp;{}&amp;{\\begin{array}{*{20}{l}}<br \/>\n{g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to x + 1}<br \/>\n\\end{array}}&amp;{}&amp;{}&amp;{\\begin{array}{*{20}{l}}<br \/>\n{h:}&amp;{\\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{1}{{{x^2} &#8211; x}}}<br \/>\n\\end{array}}<br \/>\n\\end{array}\\]<\/p>\n<\/blockquote>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[{f + g}\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{f + g}} = {D_f} \\cap {D_g} = \\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} = \\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0} \\right\\}\\]<\/p>\n<p>\\[\\left( {f + g} \\right)\\left( x \\right) = f\\left( x \\right) + g\\left( x \\right) = \\frac{1}{{{x^2}}} + x + 1 = \\frac{{{x^3} + {x^2} + 1}}{{{x^2}}},\\forall x \\in {D_{f + g}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{f + g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{{{x^3} + {x^2} + 1}}{{{x^2}}}}<br \/>\n\\end{array}\\]<\/p>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[{f \\times g}\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{f \\times g}} = {D_f} \\cap {D_g} = \\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} = \\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0} \\right\\}\\]<\/p>\n<p>\\[\\left( {f \\times g} \\right)\\left( x \\right) = f\\left( x \\right) \\times g\\left( x \\right) = \\frac{1}{{{x^2}}} \\times \\left( {x + 1} \\right) = \\frac{{x + 1}}{{{x^2}}},\\forall x \\in {D_{f \\times g}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{f \\times g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{{x + 1}}{{{x^2}}}}<br \/>\n\\end{array}\\]<\/p>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[{\\frac{f}{g}}\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{\\frac{f}{g}}} = {D_f} \\cap {D_g} \\cap \\left\\{ {x \\in \\mathbb{R}:g\\left( x \\right) \\ne 0} \\right\\} = \\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} = \\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0} \\right\\}\\]<\/p>\n<p>\\[\\left( {\\frac{f}{g}} \\right)\\left( x \\right) = \\frac{{f\\left( x \\right)}}{{g\\left( x \\right)}} = \\frac{{\\frac{1}{{{x^2}}}}}{{x + 1}} = \\frac{1}{{{x^3} + {x^2}}},\\forall x \\in {D_{\\frac{f}{g}}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{\\frac{f}{g}:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{1}{{{x^3} + {x^2}}}}<br \/>\n\\end{array}\\]<\/p>\n<\/p>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[{h &#8211; g}\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{h &#8211; g}} = {D_h} \\cap {D_g} = \\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} = \\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0,1} \\right\\}\\]<\/p>\n<p>\\[\\left( {h &#8211; g} \\right)\\left( x \\right) = h\\left( x \\right) &#8211; g\\left( x \\right) = \\frac{1}{{{x^2} &#8211; x}} &#8211; \\left( {x + 1} \\right) = \\frac{{ &#8211; {x^3} &#8211; {x^2} + {x^2} + x + 1}}{{{x^2} &#8211; x}} = \\frac{{ &#8211; {x^3} + x + 1}}{{{x^2} &#8211; x}},\\forall x \\in {D_{\\frac{f}{g}}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{h &#8211; g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1,0,1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{{ &#8211; {x^3} + x + 1}}{{{x^2} &#8211; x}}}<br \/>\n\\end{array}\\]<\/p>\n<\/p>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[\\frac{f}{h}\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{\\frac{f}{h}}} = {D_f} \\cap {D_h} \\cap \\left\\{ {x \\in \\mathbb{R}:h\\left( x \\right) \\ne 0} \\right\\} = \\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\} \\cap \\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\} = \\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\}\\]<\/p>\n<p>\\[\\left( {\\frac{f}{h}} \\right)\\left( x \\right) = \\frac{{f\\left( x \\right)}}{{h\\left( x \\right)}} = \\frac{{\\frac{1}{{{x^2}}}}}{{\\frac{1}{{{x^2} &#8211; x}}}} = \\frac{{{x^2} &#8211; x}}{{{x^2}}} = \\frac{{x\\left( {x &#8211; 1} \\right)}}{{{x^2}}} = \\frac{{x &#8211; 1}}{x},\\forall x \\in {D_{\\frac{f}{g}}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{\\frac{f}{h}:}&amp;{\\mathbb{R}\\backslash \\left\\{ {0,1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{{x &#8211; 1}}{x}}<br \/>\n\\end{array}\\]<\/p>\n<\/p>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[f \\circ g\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{f \\circ g}} = \\left\\{ {x \\in \\mathbb{R}:x \\in {D_g} \\wedge g\\left( x \\right) \\in {D_f}} \\right\\} = \\left\\{ {x \\in \\mathbb{R}:x \\in \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\wedge \\left( {x + 1} \\right) \\in \\mathbb{R}\\backslash \\left\\{ 0 \\right\\}} \\right\\} = \\left\\{ {x \\in \\mathbb{R}:x \\in \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\wedge x \\in \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\}} \\right\\} = \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\}\\]<\/p>\n<p>\\[\\left( {f \\circ g} \\right)\\left( x \\right) = f\\left( {g\\left( x \\right)} \\right) = f\\left( {x + 1} \\right) = \\frac{1}{{{{\\left( {x + 1} \\right)}^2}}},\\forall x \\in {D_{f \\circ g}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{f \\circ g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{1}{{{{\\left( {x + 1} \\right)}^2}}}}<br \/>\n\\end{array}\\]<\/p>\n<\/p>\n<hr \/>\n<p><span style=\"color: #0000ff;\">\\[g \\circ f\\]<\/span><\/p>\n<\/p>\n<p>\\[{D_{g \\circ f}} = \\left\\{ {x \\in \\mathbb{R}:x \\in {D_f} \\wedge f\\left( x \\right) \\in {D_g}} \\right\\} = \\left\\{ {x \\in \\mathbb{R}:x \\in \\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\wedge \\left( {\\frac{1}{{{x^2}}}} \\right) \\in \\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\}} \\right\\} = \\left\\{ {x \\in \\mathbb{R}:x \\in \\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\wedge x \\in \\mathbb{R}\\backslash \\left\\{ 0 \\right\\}} \\right\\} = \\mathbb{R}\\backslash \\left\\{ 0 \\right\\}\\]<\/p>\n<p>\\[\\left( {g \\circ f} \\right)\\left( x \\right) = g\\left( {f\\left( x \\right)} \\right) = g\\left( {\\frac{1}{{{x^2}}}} \\right) = \\frac{1}{{{x^2}}} + 1 = \\frac{{{x^2} + 1}}{{{x^2}}},\\forall x \\in {D_{f \\circ g}}\\]<\/p>\n<p>\\[\\begin{array}{*{20}{l}}<br \/>\n{g \\circ f:}&amp;{\\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\to \\mathbb{R}} \\\\<br \/>\n{}&amp;{x \\to \\frac{{{x^2} + 1}}{{{x^2}}}}<br \/>\n\\end{array}\\]<\/p>\n<div class='GTTabsNavigation' style='display:none'><span class='GTTabs_nav_prev'><a href='#GTTabs_ul_11826' onClick='GTTabs_show(0,11826)'>&lt;&lt; Enunciado<\/a><\/span><\/div><\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>Enunciado Resolu\u00e7\u00e3o Enunciado Considere as fun\u00e7\u00f5es definidas por: \u00a0\\[\\begin{array}{*{20}{l}} {\\begin{array}{*{20}{l}} {f:}&amp;{\\mathbb{R}\\backslash \\left\\{ 0 \\right\\} \\to \\mathbb{R}} \\\\ {}&amp;{x \\to \\frac{1}{{{x^2}}}} \\end{array}}&amp;{}&amp;{}&amp;{\\begin{array}{*{20}{l}} {g:}&amp;{\\mathbb{R}\\backslash \\left\\{ { &#8211; 1} \\right\\} \\to \\mathbb{R}} \\\\ {}&amp;{x \\to x +&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":19175,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[98,97,153,147],"tags":[422,154,363,366,364,365],"series":[],"class_list":["post-11826","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-11--ano","category-aplicando","category-funcao-composta","category-operacoes-com-funcoes","tag-11-o-ano","tag-funcao-composta-2","tag-funcao-diferenca","tag-funcao-produto","tag-funcao-quociente","tag-funcao-soma"],"views":3702,"jetpack_featured_media_url":"https:\/\/www.acasinhadamatematica.pt\/wp-content\/uploads\/2021\/12\/Mat66.png","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=\/wp\/v2\/posts\/11826","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11826"}],"version-history":[{"count":0,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=\/wp\/v2\/posts\/11826\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=\/wp\/v2\/media\/19175"}],"wp:attachment":[{"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11826"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11826"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11826"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/www.acasinhadamatematica.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fseries&post=11826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}