<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1794-9165</journal-id>
<journal-title><![CDATA[Ingeniería y Ciencia]]></journal-title>
<abbrev-journal-title><![CDATA[ing.cienc.]]></abbrev-journal-title>
<issn>1794-9165</issn>
<publisher>
<publisher-name><![CDATA[Escuela de Ciencias y Humanidades y Escuela de Ingeniería de la Universidad EAFIT]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1794-91652018000100011</article-id>
<article-id pub-id-type="doi">10.17230/ingciencia.14.27.1</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[La &#966;&#8722;ecuación de Tricomi]]></article-title>
<article-title xml:lang="en"><![CDATA[Tricomi&#8217;s &#966;-equation]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Castro G]]></surname>
<given-names><![CDATA[Diego A]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gutiérrez G]]></surname>
<given-names><![CDATA[Alexander]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Tecnológica de Pereira  ]]></institution>
<addr-line><![CDATA[Risaralda ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad Tecnológica de Pereira  ]]></institution>
<addr-line><![CDATA[Risaralda ]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2018</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2018</year>
</pub-date>
<volume>14</volume>
<numero>27</numero>
<fpage>11</fpage>
<lpage>28</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S1794-91652018000100011&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S1794-91652018000100011&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S1794-91652018000100011&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen En este artículo se estudia una ecuación diferencial no lineal autónoma que modela el movimiento de un &#966; -péndulo amortiguado con forzamiento constante. En el caso disipativo se presentan dos resultados, por un lado, usando la aplicación de Poincaré y funciones de energía, se establece un criterio suficiente para determinar la existencia, unicidad y estabilidad asintótica de una solución periódica de segunda clase y por otro lado, se presenta un criterio con el que se estima analíticamente la cuenca de atracción de un equilibrio asintóticamente estable con ayuda del principio de invarianza de Lasalle. Mientras que en el caso conservativo se dan condiciones necesarias para que la imagen de la función periodo esté definida en un intervalo no acotado. Los resultados obtenidos en el caso disipativo son una generalización de los establecidos por Tricomi en el caso newtoniano.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract In this paper we study an autonomous nonlinear differential equation that models the movement of a damped &#966;-pendulum with constant forcing. In the dissipative case, two results are presented, on the one hand, using the application of Poincaré and energy functions, a sufficient criterion is established to guarantee the existence, uniqueness and asymptotic stability of a periodic solution of the second kind and on the other hand, a criterion is presented with which the basin of attraction of an asymptotically stable equilibrium is estimated analytically with the help of the Lasalle&#8217;s invariance principle. While in the conservative case there are necessary conditions for range of the period function to be defined in an unbounded interval. The results obtained in the dissipative case are a generalization of those established by Tricomi in the newtonian case.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Soluciones periódicas]]></kwd>
<kwd lng="es"><![CDATA[atractores]]></kwd>
<kwd lng="es"><![CDATA[estabilidad]]></kwd>
<kwd lng="en"><![CDATA[Periodic solutions]]></kwd>
<kwd lng="en"><![CDATA[attractors]]></kwd>
<kwd lng="en"><![CDATA[stability]]></kwd>
</kwd-group>
</article-meta>
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