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(ctgx+3)^2+2a^3+3a^2=(a^2+2a+3)*(ctgx+3) la ecuación

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Solución numérica:

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Solución

Ha introducido [src]
            2      3      2   / 2          \             
(cot(x) + 3)  + 2*a  + 3*a  = \a  + 2*a + 3/*(cot(x) + 3)
3a2+(2a3+(cot(x)+3)2)=((a2+2a)+3)(cot(x)+3)3 a^{2} + \left(2 a^{3} + \left(\cot{\left(x \right)} + 3\right)^{2}\right) = \left(\left(a^{2} + 2 a\right) + 3\right) \left(\cot{\left(x \right)} + 3\right)
Solución detallada
Tenemos la ecuación
3a2+(2a3+(cot(x)+3)2)=((a2+2a)+3)(cot(x)+3)3 a^{2} + \left(2 a^{3} + \left(\cot{\left(x \right)} + 3\right)^{2}\right) = \left(\left(a^{2} + 2 a\right) + 3\right) \left(\cot{\left(x \right)} + 3\right)
cambiamos
2a3+3a2+(cot(x)+3)2(cot(x)+3)(a2+2a+3)=02 a^{3} + 3 a^{2} + \left(\cot{\left(x \right)} + 3\right)^{2} - \left(\cot{\left(x \right)} + 3\right) \left(a^{2} + 2 a + 3\right) = 0
(3a2+(2a3+(cot(x)+3)2))((a2+2a)+3)(cot(x)+3)=0\left(3 a^{2} + \left(2 a^{3} + \left(\cot{\left(x \right)} + 3\right)^{2}\right)\right) - \left(\left(a^{2} + 2 a\right) + 3\right) \left(\cot{\left(x \right)} + 3\right) = 0
Sustituimos
w=cot(x)w = \cot{\left(x \right)}
Abramos la expresión en la ecuación
2a3+3a2+(w+3)2(w+3)(a2+2a+3)=02 a^{3} + 3 a^{2} + \left(w + 3\right)^{2} - \left(w + 3\right) \left(a^{2} + 2 a + 3\right) = 0
Obtenemos la ecuación cuadrática
2a3a2w2aw6a+w2+3w=02 a^{3} - a^{2} w - 2 a w - 6 a + w^{2} + 3 w = 0
Es la ecuación de la forma
a*w^2 + b*w + c = 0

La ecuación cuadrática puede ser resuelta
con la ayuda del discriminante.
Las raíces de la ecuación cuadrática:
w1=Db2aw_{1} = \frac{\sqrt{D} - b}{2 a}
w2=Db2aw_{2} = \frac{- \sqrt{D} - b}{2 a}
donde D = b^2 - 4*a*c es el discriminante.
Como
a=1a = 1
b=a22a+3b = - a^{2} - 2 a + 3
c=2a36ac = 2 a^{3} - 6 a
, entonces
D = b^2 - 4 * a * c = 

(3 - a^2 - 2*a)^2 - 4 * (1) * (-6*a + 2*a^3) = (3 - a^2 - 2*a)^2 - 8*a^3 + 24*a

La ecuación tiene dos raíces.
w1 = (-b + sqrt(D)) / (2*a)

w2 = (-b - sqrt(D)) / (2*a)

o
w1=a22+a+8a3+24a+(a22a+3)2232w_{1} = \frac{a^{2}}{2} + a + \frac{\sqrt{- 8 a^{3} + 24 a + \left(- a^{2} - 2 a + 3\right)^{2}}}{2} - \frac{3}{2}
w2=a22+a8a3+24a+(a22a+3)2232w_{2} = \frac{a^{2}}{2} + a - \frac{\sqrt{- 8 a^{3} + 24 a + \left(- a^{2} - 2 a + 3\right)^{2}}}{2} - \frac{3}{2}
hacemos cambio inverso
cot(x)=w\cot{\left(x \right)} = w
sustituimos w:
Gráfica
Respuesta rápida [src]
x1 = I*im(acot(2*a)) + re(acot(2*a))
x1=re(acot(2a))+iim(acot(2a))x_{1} = \operatorname{re}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(2 a \right)}\right)}
         /    /      2\\     /    /      2\\
x2 = I*im\acot\-3 + a // + re\acot\-3 + a //
x2=re(acot(a23))+iim(acot(a23))x_{2} = \operatorname{re}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)}
x2 = re(acot(a^2 - 3)) + i*im(acot(a^2 - 3))
Suma y producto de raíces [src]
suma
                                      /    /      2\\     /    /      2\\
I*im(acot(2*a)) + re(acot(2*a)) + I*im\acot\-3 + a // + re\acot\-3 + a //
(re(acot(2a))+iim(acot(2a)))+(re(acot(a23))+iim(acot(a23)))\left(\operatorname{re}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(2 a \right)}\right)}\right) + \left(\operatorname{re}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)}\right)
=
                      /    /      2\\                     /    /      2\\
I*im(acot(2*a)) + I*im\acot\-3 + a // + re(acot(2*a)) + re\acot\-3 + a //
re(acot(2a))+re(acot(a23))+iim(acot(2a))+iim(acot(a23))\operatorname{re}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + \operatorname{re}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)}
producto
                                  /    /    /      2\\     /    /      2\\\
(I*im(acot(2*a)) + re(acot(2*a)))*\I*im\acot\-3 + a // + re\acot\-3 + a ///
(re(acot(2a))+iim(acot(2a)))(re(acot(a23))+iim(acot(a23)))\left(\operatorname{re}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(2 a \right)}\right)}\right) \left(\operatorname{re}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)}\right)
=
                                  /    /    /      2\\     /    /      2\\\
(I*im(acot(2*a)) + re(acot(2*a)))*\I*im\acot\-3 + a // + re\acot\-3 + a ///
(re(acot(2a))+iim(acot(2a)))(re(acot(a23))+iim(acot(a23)))\left(\operatorname{re}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(2 a \right)}\right)}\right) \left(\operatorname{re}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(a^{2} - 3 \right)}\right)}\right)
(i*im(acot(2*a)) + re(acot(2*a)))*(i*im(acot(-3 + a^2)) + re(acot(-3 + a^2)))