(x-3)^4-(x-3)^2-10=0 la ecuación
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Solución
Solución detallada
Tenemos la ecuación:
( ( x − 3 ) 4 − ( x − 3 ) 2 ) − 10 = 0 \left(\left(x - 3\right)^{4} - \left(x - 3\right)^{2}\right) - 10 = 0 ( ( x − 3 ) 4 − ( x − 3 ) 2 ) − 10 = 0 Sustituimos
v = ( x − 3 ) 2 v = \left(x - 3\right)^{2} v = ( x − 3 ) 2 entonces la ecuación será así:
v 2 − v − 10 = 0 v^{2} - v - 10 = 0 v 2 − v − 10 = 0 Es la ecuación de la forma
a*v^2 + b*v + c = 0 La ecuación cuadrática puede ser resuelta
con la ayuda del discriminante.
Las raíces de la ecuación cuadrática:
v 1 = D − b 2 a v_{1} = \frac{\sqrt{D} - b}{2 a} v 1 = 2 a D − b v 2 = − D − b 2 a v_{2} = \frac{- \sqrt{D} - b}{2 a} v 2 = 2 a − D − b donde D = b^2 - 4*a*c es el discriminante.
Como
a = 1 a = 1 a = 1 b = − 1 b = -1 b = − 1 c = − 10 c = -10 c = − 10 , entonces
D = b^2 - 4 * a * c = (-1)^2 - 4 * (1) * (-10) = 41 Como D > 0 la ecuación tiene dos raíces.
v1 = (-b + sqrt(D)) / (2*a) v2 = (-b - sqrt(D)) / (2*a) o
v 1 = 1 2 + 41 2 v_{1} = \frac{1}{2} + \frac{\sqrt{41}}{2} v 1 = 2 1 + 2 41 v 2 = 1 2 − 41 2 v_{2} = \frac{1}{2} - \frac{\sqrt{41}}{2} v 2 = 2 1 − 2 41 Entonces la respuesta definitiva es:
Como
v = ( x − 3 ) 2 v = \left(x - 3\right)^{2} v = ( x − 3 ) 2 entonces
x 1 = v 1 + 3 x_{1} = \sqrt{v_{1}} + 3 x 1 = v 1 + 3 x 2 = 3 − v 1 x_{2} = 3 - \sqrt{v_{1}} x 2 = 3 − v 1 x 3 = v 2 + 3 x_{3} = \sqrt{v_{2}} + 3 x 3 = v 2 + 3 x 4 = 3 − v 2 x_{4} = 3 - \sqrt{v_{2}} x 4 = 3 − v 2 entonces:
x 1 = x_{1} = x 1 = ( 1 2 + 41 2 ) 1 2 1 + 3 1 = 1 2 + 41 2 + 3 \frac{\left(\frac{1}{2} + \frac{\sqrt{41}}{2}\right)^{\frac{1}{2}}}{1} + \frac{3}{1} = \sqrt{\frac{1}{2} + \frac{\sqrt{41}}{2}} + 3 1 ( 2 1 + 2 41 ) 2 1 + 1 3 = 2 1 + 2 41 + 3 x 2 = x_{2} = x 2 = ( − 1 ) ( 1 2 + 41 2 ) 1 2 1 + 3 1 = 3 − 1 2 + 41 2 \frac{\left(-1\right) \left(\frac{1}{2} + \frac{\sqrt{41}}{2}\right)^{\frac{1}{2}}}{1} + \frac{3}{1} = 3 - \sqrt{\frac{1}{2} + \frac{\sqrt{41}}{2}} 1 ( − 1 ) ( 2 1 + 2 41 ) 2 1 + 1 3 = 3 − 2 1 + 2 41 x 3 = x_{3} = x 3 = 3 1 + ( 1 2 − 41 2 ) 1 2 1 = 3 + 1 2 − 41 2 \frac{3}{1} + \frac{\left(\frac{1}{2} - \frac{\sqrt{41}}{2}\right)^{\frac{1}{2}}}{1} = 3 + \sqrt{\frac{1}{2} - \frac{\sqrt{41}}{2}} 1 3 + 1 ( 2 1 − 2 41 ) 2 1 = 3 + 2 1 − 2 41 x 4 = x_{4} = x 4 = 3 1 + ( − 1 ) ( 1 2 − 41 2 ) 1 2 1 = 3 − 1 2 − 41 2 \frac{3}{1} + \frac{\left(-1\right) \left(\frac{1}{2} - \frac{\sqrt{41}}{2}\right)^{\frac{1}{2}}}{1} = 3 - \sqrt{\frac{1}{2} - \frac{\sqrt{41}}{2}} 1 3 + 1 ( − 1 ) ( 2 1 − 2 41 ) 2 1 = 3 − 2 1 − 2 41
Gráfica
2 4 6 8 10 12 14 16 18 20 22 40000 -20000
Suma y producto de raíces
[src]
____________ ____________ _____________ _____________
___ / ____ ___ / ____ ___ / ____ ___ / ____
\/ 2 *\/ 1 + \/ 41 \/ 2 *\/ 1 + \/ 41 I*\/ 2 *\/ -1 + \/ 41 I*\/ 2 *\/ -1 + \/ 41
3 - --------------------- + 3 + --------------------- + 3 - ------------------------ + 3 + ------------------------
2 2 2 2
( ( ( − 2 1 + 41 2 + 3 ) + ( 2 1 + 41 2 + 3 ) ) + ( 3 − 2 i − 1 + 41 2 ) ) + ( 3 + 2 i − 1 + 41 2 ) \left(\left(\left(- \frac{\sqrt{2} \sqrt{1 + \sqrt{41}}}{2} + 3\right) + \left(\frac{\sqrt{2} \sqrt{1 + \sqrt{41}}}{2} + 3\right)\right) + \left(3 - \frac{\sqrt{2} i \sqrt{-1 + \sqrt{41}}}{2}\right)\right) + \left(3 + \frac{\sqrt{2} i \sqrt{-1 + \sqrt{41}}}{2}\right) ( ( ( − 2 2 1 + 41 + 3 ) + ( 2 2 1 + 41 + 3 ) ) + ( 3 − 2 2 i − 1 + 41 ) ) + ( 3 + 2 2 i − 1 + 41 )
/ ____________\ / ____________\ / _____________\ / _____________\
| ___ / ____ | | ___ / ____ | | ___ / ____ | | ___ / ____ |
| \/ 2 *\/ 1 + \/ 41 | | \/ 2 *\/ 1 + \/ 41 | | I*\/ 2 *\/ -1 + \/ 41 | | I*\/ 2 *\/ -1 + \/ 41 |
|3 - ---------------------|*|3 + ---------------------|*|3 - ------------------------|*|3 + ------------------------|
\ 2 / \ 2 / \ 2 / \ 2 /
( − 2 1 + 41 2 + 3 ) ( 2 1 + 41 2 + 3 ) ( 3 − 2 i − 1 + 41 2 ) ( 3 + 2 i − 1 + 41 2 ) \left(- \frac{\sqrt{2} \sqrt{1 + \sqrt{41}}}{2} + 3\right) \left(\frac{\sqrt{2} \sqrt{1 + \sqrt{41}}}{2} + 3\right) \left(3 - \frac{\sqrt{2} i \sqrt{-1 + \sqrt{41}}}{2}\right) \left(3 + \frac{\sqrt{2} i \sqrt{-1 + \sqrt{41}}}{2}\right) ( − 2 2 1 + 41 + 3 ) ( 2 2 1 + 41 + 3 ) ( 3 − 2 2 i − 1 + 41 ) ( 3 + 2 2 i − 1 + 41 )
____________
___ / ____
\/ 2 *\/ 1 + \/ 41
x1 = 3 - ---------------------
2
x 1 = − 2 1 + 41 2 + 3 x_{1} = - \frac{\sqrt{2} \sqrt{1 + \sqrt{41}}}{2} + 3 x 1 = − 2 2 1 + 41 + 3
____________
___ / ____
\/ 2 *\/ 1 + \/ 41
x2 = 3 + ---------------------
2
x 2 = 2 1 + 41 2 + 3 x_{2} = \frac{\sqrt{2} \sqrt{1 + \sqrt{41}}}{2} + 3 x 2 = 2 2 1 + 41 + 3
_____________
___ / ____
I*\/ 2 *\/ -1 + \/ 41
x3 = 3 - ------------------------
2
x 3 = 3 − 2 i − 1 + 41 2 x_{3} = 3 - \frac{\sqrt{2} i \sqrt{-1 + \sqrt{41}}}{2} x 3 = 3 − 2 2 i − 1 + 41
_____________
___ / ____
I*\/ 2 *\/ -1 + \/ 41
x4 = 3 + ------------------------
2
x 4 = 3 + 2 i − 1 + 41 2 x_{4} = 3 + \frac{\sqrt{2} i \sqrt{-1 + \sqrt{41}}}{2} x 4 = 3 + 2 2 i − 1 + 41
x4 = 3 + sqrt(2)*i*sqrt(-1 + sqrt(41))/2
x2 = 3.0 - 1.6436429413703*i
x3 = 3.0 + 1.6436429413703*i