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Considere la ecuación de la circunferencia $\\simplify[all]{(x-{a})^2+(y-{b})^2}=\\simplify[basic]{{r}^2}$.

", "advice": "

La intersección en el eje $x$ es el valor de $x$ cuando $y = 0$, es decir, el valor de $x$ donde la gráfica alcanza al eje $x$.

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Para encontrar esto, sustituye $y=0$ en su ecuación:

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\\[\\simplify[all]{(x-{a})^2}+\\simplify[basic]{(-{b})^2}={r}^2\\]

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y resuelve para $x$:

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify[all]{(x-{a})^2}$$=$$\\simplify[basic]{{r}^2-{abs(b)}^2}$
$\\simplify[all]{(x-{a})}$$=$$\\pm\\sqrt{\\simplify[basic]{{r}^2-{abs(b)}^2}}$
$=$$\\pm\\sqrt{\\var{xdet}}$
$=$$\\pm$$\\var{xug}$
$x$$=$$\\var{a}$$\\pm\\var{xug}$
$x$$=$$\\var{a-xug}$$,\\var{a+xug}$
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Si consideramos solo números reales, la raíz cuadrada de un número negativo no es un número real, no hay intersecciones en el eje $x$.                         

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 Si consideramos (mas o menos) la raíz cuadrada de cero solo tenemos una intersección con el eje $x$, $x=\\var{a}$. 

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En este caso tenemos dos intersecciones en el eje $x$ distintas

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La intersección en el eje $y$ es el valor de $y$ cuando $x = 0$, es decir, el valor de $y$ donde la gráfica alcanza al eje $y$.

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Para encontrar esto, reemplazamos $x=0$ sobre la ecuación:

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\\[\\simplify[basic]{(-{a})^2}+\\simplify[all]{(y-{b})^2}=\\simplify[basic]{{r}^2}\\]

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y resuelve para $y$:

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify[all]{(y-{b})^2}$$=$$\\simplify[basic]{{r}^2-{abs(a)}^2}$
$\\simplify[all]{(y-{b})}$$=$$\\pm\\sqrt{\\simplify[basic]{{r}^2-{abs(a)}^2}}$
$=$$\\pm\\sqrt{\\var{ydet}}$
$=$$\\pm$$\\var{yug}$
$y$$=$$\\var{b}$$\\pm\\var{yug}$
$y$$=$$\\var{b-yug}$$,\\var{b+yug}$   
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Si trabajamos con números reales, la raíz cuadrada de un número negativo no es real, no existe intersección en el eje $y$.

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Si consideramos (más o menos) la raíz cuadrada de cero, solo tenemos una intersección en el eje $y$, $y=\\var{b}$. 

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En este caso tenemos dos intersecciones - distintas - en el eje $y$.

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Las intersecciones de la gráfica con el eje $x$ de esta ecuación son:   [[0]].

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Indicación: 

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Si no existe intersección, ingrese sólo set()

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Si existe una intersección, por ejemplo $x=5$, ingrese set(5)

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Si existen dos intersecciones, por ejemplo $x=-2$ y $x=1.5$, ingrese set(-2,1.5)

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Las intersecciones de la gráfica con el eje $y$ de esta ecuación son: [[0]].

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Indicación:

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Si no existe intersección, ingrese set()

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Si existe solo una intersección, por ejemplo $y=5$, ingrese set(5)

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Si existen dos intersecciones, por ejemplo $y=-2$ y $y=1.5$, ingrese set(-2,1.5)

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