(ctgx+3)^2+2a^3+3a^2=(a^2+2a+3)*(ctgx+3) la ecuación
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Solución
Solución detallada
Tenemos la ecuación
3 a 2 + ( 2 a 3 + ( cot ( x ) + 3 ) 2 ) = ( ( a 2 + 2 a ) + 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) 3 a 2 + ( 2 a 3 + ( cot ( x ) + 3 ) 2 ) = ( ( a 2 + 2 a ) + 3 ) ( cot ( x ) + 3 ) cambiamos
2 a 3 + 3 a 2 + ( cot ( x ) + 3 ) 2 − ( cot ( x ) + 3 ) ( a 2 + 2 a + 3 ) = 0 2 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 2 a 3 + 3 a 2 + ( cot ( x ) + 3 ) 2 − ( cot ( x ) + 3 ) ( a 2 + 2 a + 3 ) = 0 ( 3 a 2 + ( 2 a 3 + ( cot ( x ) + 3 ) 2 ) ) − ( ( a 2 + 2 a ) + 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 ( 3 a 2 + ( 2 a 3 + ( cot ( x ) + 3 ) 2 ) ) − ( ( a 2 + 2 a ) + 3 ) ( cot ( x ) + 3 ) = 0 Sustituimos
w = cot ( x ) w = \cot{\left(x \right)} w = cot ( x ) Abramos la expresión en la ecuación
2 a 3 + 3 a 2 + ( w + 3 ) 2 − ( w + 3 ) ( a 2 + 2 a + 3 ) = 0 2 a^{3} + 3 a^{2} + \left(w + 3\right)^{2} - \left(w + 3\right) \left(a^{2} + 2 a + 3\right) = 0 2 a 3 + 3 a 2 + ( w + 3 ) 2 − ( w + 3 ) ( a 2 + 2 a + 3 ) = 0 Obtenemos la ecuación cuadrática
2 a 3 − a 2 w − 2 a w − 6 a + w 2 + 3 w = 0 2 a^{3} - a^{2} w - 2 a w - 6 a + w^{2} + 3 w = 0 2 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:
w 1 = D − b 2 a w_{1} = \frac{\sqrt{D} - b}{2 a} w 1 = 2 a D − b w 2 = − D − b 2 a w_{2} = \frac{- \sqrt{D} - b}{2 a} w 2 = 2 a − D − b donde D = b^2 - 4*a*c es el discriminante.
Como
a = 1 a = 1 a = 1 b = − a 2 − 2 a + 3 b = - a^{2} - 2 a + 3 b = − a 2 − 2 a + 3 c = 2 a 3 − 6 a c = 2 a^{3} - 6 a c = 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
w 1 = a 2 2 + a + − 8 a 3 + 24 a + ( − a 2 − 2 a + 3 ) 2 2 − 3 2 w_{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} w 1 = 2 a 2 + a + 2 − 8 a 3 + 24 a + ( − a 2 − 2 a + 3 ) 2 − 2 3 w 2 = a 2 2 + a − − 8 a 3 + 24 a + ( − a 2 − 2 a + 3 ) 2 2 − 3 2 w_{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} w 2 = 2 a 2 + a − 2 − 8 a 3 + 24 a + ( − a 2 − 2 a + 3 ) 2 − 2 3 hacemos cambio inverso
cot ( x ) = w \cot{\left(x \right)} = w cot ( x ) = w sustituimos w:
x1 = I*im(acot(2*a)) + re(acot(2*a))
x 1 = re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) x_{1} = \operatorname{re}{\left(\operatorname{acot}{\left(2 a \right)}\right)} + i \operatorname{im}{\left(\operatorname{acot}{\left(2 a \right)}\right)} x 1 = re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) )
/ / 2\\ / / 2\\
x2 = I*im\acot\-3 + a // + re\acot\-3 + a //
x 2 = re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) 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)} x 2 = re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) )
x2 = re(acot(a^2 - 3)) + i*im(acot(a^2 - 3))
Suma y producto de raíces
[src]
/ / 2\\ / / 2\\
I*im(acot(2*a)) + re(acot(2*a)) + I*im\acot\-3 + a // + re\acot\-3 + a //
( re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) ) + ( re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) ) \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) ( re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) ) + ( re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) )
/ / 2\\ / / 2\\
I*im(acot(2*a)) + I*im\acot\-3 + a // + re(acot(2*a)) + re\acot\-3 + a //
re ( acot ( 2 a ) ) + re ( acot ( a 2 − 3 ) ) + i im ( acot ( 2 a ) ) + i im ( acot ( a 2 − 3 ) ) \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)} re ( acot ( 2 a ) ) + re ( acot ( a 2 − 3 ) ) + i im ( acot ( 2 a ) ) + i im ( acot ( a 2 − 3 ) )
/ / / 2\\ / / 2\\\
(I*im(acot(2*a)) + re(acot(2*a)))*\I*im\acot\-3 + a // + re\acot\-3 + a ///
( re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) ) ( re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) ) \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) ( re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) ) ( re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) )
/ / / 2\\ / / 2\\\
(I*im(acot(2*a)) + re(acot(2*a)))*\I*im\acot\-3 + a // + re\acot\-3 + a ///
( re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) ) ( re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) ) \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) ( re ( acot ( 2 a ) ) + i im ( acot ( 2 a ) ) ) ( re ( acot ( a 2 − 3 ) ) + i im ( acot ( a 2 − 3 ) ) )
(i*im(acot(2*a)) + re(acot(2*a)))*(i*im(acot(-3 + a^2)) + re(acot(-3 + a^2)))