-2x^3+8*x-9,8696=0 la ecuación
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Solución
Teorema de Cardano-Vieta
reescribamos la ecuación
$$\left(- 2 x^{3} + 8 x\right) - 9.8696 = 0$$
de
$$a x^{3} + b x^{2} + c x + d = 0$$
como ecuación cúbica reducida
$$x^{3} + \frac{b x^{2}}{a} + \frac{c x}{a} + \frac{d}{a} = 0$$
$$x^{3} - 4 x + 4.9348 = 0$$
$$p x^{2} + q x + v + x^{3} = 0$$
donde
$$p = \frac{b}{a}$$
$$p = 0$$
$$q = \frac{c}{a}$$
$$q = -4$$
$$v = \frac{d}{a}$$
$$v = 4.9348$$
Fórmulas de Cardano-Vieta
$$x_{1} + x_{2} + x_{3} = - p$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = q$$
$$x_{1} x_{2} x_{3} = v$$
$$x_{1} + x_{2} + x_{3} = 0$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = -4$$
$$x_{1} x_{2} x_{3} = 4.9348$$
$$x_{1} = -2.45204492278324$$
x2 = 1.22602246139162 - 0.713717890703523*I
$$x_{2} = 1.22602246139162 - 0.713717890703523 i$$
x3 = 1.22602246139162 + 0.713717890703523*I
$$x_{3} = 1.22602246139162 + 0.713717890703523 i$$
x3 = 1.22602246139162 + 0.713717890703523*i
Suma y producto de raíces
[src]
-2.45204492278324 + 1.22602246139162 - 0.713717890703523*I + 1.22602246139162 + 0.713717890703523*I
$$\left(-2.45204492278324 + \left(1.22602246139162 - 0.713717890703523 i\right)\right) + \left(1.22602246139162 + 0.713717890703523 i\right)$$
$$0$$
-2.45204492278324*(1.22602246139162 - 0.713717890703523*I)*(1.22602246139162 + 0.713717890703523*I)
$$- 2.45204492278324 \left(1.22602246139162 - 0.713717890703523 i\right) \left(1.22602246139162 + 0.713717890703523 i\right)$$
$$-4.9348$$
x1 = 1.22602246139162 + 0.713717890703523*i
x3 = 1.22602246139162 - 0.713717890703523*i
x3 = 1.22602246139162 - 0.713717890703523*i