Sr Examen

Otras calculadoras


2*x^3+6*x+9=0

2*x^3+6*x+9=0 la ecuación

El profesor se sorprenderá mucho al ver tu solución correcta😉

v

Solución numérica:

Buscar la solución numérica en el intervalo [, ]

Solución

Ha introducido [src]
   3              
2*x  + 6*x + 9 = 0
$$\left(2 x^{3} + 6 x\right) + 9 = 0$$
Teorema de Cardano-Vieta
reescribamos la ecuación
$$\left(2 x^{3} + 6 x\right) + 9 = 0$$
de
$$a x^{3} + b x^{2} + c x + d = 0$$
como ecuación cúbica reducida
$$x^{3} + \frac{b x^{2}}{a} + \frac{c x}{a} + \frac{d}{a} = 0$$
$$x^{3} + 3 x + \frac{9}{2} = 0$$
$$p x^{2} + q x + v + x^{3} = 0$$
donde
$$p = \frac{b}{a}$$
$$p = 0$$
$$q = \frac{c}{a}$$
$$q = 3$$
$$v = \frac{d}{a}$$
$$v = \frac{9}{2}$$
Fórmulas de Cardano-Vieta
$$x_{1} + x_{2} + x_{3} = - p$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = q$$
$$x_{1} x_{2} x_{3} = v$$
$$x_{1} + x_{2} + x_{3} = 0$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = 3$$
$$x_{1} x_{2} x_{3} = \frac{9}{2}$$
Gráfica
Suma y producto de raíces [src]
suma
                                  _________________     /           _________________                           \                                     _________________     /                                        _________________\                                 _________________
                                 /            ____      |          /            ____                            |                                    /            ____      |                                       /            ____ |                                /            ____ 
                                /  243   27*\/ 97       |  ___    /  243   27*\/ 97                             |                                   /  243   27*\/ 97       |                               ___    /  243   27*\/ 97  |                               /  243   27*\/ 97  
                             3 /   --- + ---------      |\/ 3 *3 /   --- + ---------                ___         |                                3 /   --- + ---------      |              ___            \/ 3 *3 /   --- + --------- |                            3 /   --- + --------- 
             3               \/     4        4          |      \/     4        4                3*\/ 3          |                3               \/     4        4          |          3*\/ 3                   \/     4        4     |             3              \/     4        4     
- ------------------------ + ---------------------- + I*|---------------------------- + ------------------------| + - ------------------------ + ---------------------- + I*|- ------------------------ - ----------------------------| + ---------------------- - ----------------------
         _________________             6                |             6                        _________________|            _________________             6                |         _________________                6              |        _________________             3           
        /            ____                               |                                     /            ____ |           /            ____                               |        /            ____                                |       /            ____                          
       /  243   27*\/ 97                                |                                    /  243   27*\/ 97  |          /  243   27*\/ 97                                |       /  243   27*\/ 97                                 |      /  243   27*\/ 97                           
  2*3 /   --- + ---------                               |                               2*3 /   --- + --------- |     2*3 /   --- + ---------                               |  2*3 /   --- + ---------                                |   3 /   --- + ---------                          
    \/     4        4                                   \                                 \/     4        4     /       \/     4        4                                   \    \/     4        4                                    /   \/     4        4                              
$$\left(- \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{3} + \frac{3}{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}\right) + \left(\left(- \frac{3}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} - \frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}\right)\right) + \left(- \frac{3}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} + i \left(\frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6}\right)\right)\right)$$
=
  /                                        _________________\     /           _________________                           \
  |                                       /            ____ |     |          /            ____                            |
  |                               ___    /  243   27*\/ 97  |     |  ___    /  243   27*\/ 97                             |
  |              ___            \/ 3 *3 /   --- + --------- |     |\/ 3 *3 /   --- + ---------                ___         |
  |          3*\/ 3                   \/     4        4     |     |      \/     4        4                3*\/ 3          |
I*|- ------------------------ - ----------------------------| + I*|---------------------------- + ------------------------|
  |         _________________                6              |     |             6                        _________________|
  |        /            ____                                |     |                                     /            ____ |
  |       /  243   27*\/ 97                                 |     |                                    /  243   27*\/ 97  |
  |  2*3 /   --- + ---------                                |     |                               2*3 /   --- + --------- |
  \    \/     4        4                                    /     \                                 \/     4        4     /
$$i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} - \frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}\right) + i \left(\frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6}\right)$$
producto
/                                  _________________     /           _________________                           \\ /                                  _________________     /                                        _________________\\ /                              _________________\
|                                 /            ____      |          /            ____                            || |                                 /            ____      |                                       /            ____ || |                             /            ____ |
|                                /  243   27*\/ 97       |  ___    /  243   27*\/ 97                             || |                                /  243   27*\/ 97       |                               ___    /  243   27*\/ 97  || |                            /  243   27*\/ 97  |
|                             3 /   --- + ---------      |\/ 3 *3 /   --- + ---------                ___         || |                             3 /   --- + ---------      |              ___            \/ 3 *3 /   --- + --------- || |                         3 /   --- + --------- |
|             3               \/     4        4          |      \/     4        4                3*\/ 3          || |             3               \/     4        4          |          3*\/ 3                   \/     4        4     || |          3              \/     4        4     |
|- ------------------------ + ---------------------- + I*|---------------------------- + ------------------------||*|- ------------------------ + ---------------------- + I*|- ------------------------ - ----------------------------||*|---------------------- - ----------------------|
|         _________________             6                |             6                        _________________|| |         _________________             6                |         _________________                6              || |     _________________             3           |
|        /            ____                               |                                     /            ____ || |        /            ____                               |        /            ____                                || |    /            ____                          |
|       /  243   27*\/ 97                                |                                    /  243   27*\/ 97  || |       /  243   27*\/ 97                                |       /  243   27*\/ 97                                 || |   /  243   27*\/ 97                           |
|  2*3 /   --- + ---------                               |                               2*3 /   --- + --------- || |  2*3 /   --- + ---------                               |  2*3 /   --- + ---------                                || |3 /   --- + ---------                          |
\    \/     4        4                                   \                                 \/     4        4     // \    \/     4        4                                   \    \/     4        4                                    // \\/     4        4                              /
$$\left(- \frac{3}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} + i \left(\frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6}\right)\right) \left(- \frac{3}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} - \frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}\right)\right) \left(- \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{3} + \frac{3}{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}\right)$$
=
-9/2
$$- \frac{9}{2}$$
-9/2
Respuesta rápida [src]
                                       _________________     /           _________________                           \
                                      /            ____      |          /            ____                            |
                                     /  243   27*\/ 97       |  ___    /  243   27*\/ 97                             |
                                  3 /   --- + ---------      |\/ 3 *3 /   --- + ---------                ___         |
                  3               \/     4        4          |      \/     4        4                3*\/ 3          |
x1 = - ------------------------ + ---------------------- + I*|---------------------------- + ------------------------|
              _________________             6                |             6                        _________________|
             /            ____                               |                                     /            ____ |
            /  243   27*\/ 97                                |                                    /  243   27*\/ 97  |
       2*3 /   --- + ---------                               |                               2*3 /   --- + --------- |
         \/     4        4                                   \                                 \/     4        4     /
$$x_{1} = - \frac{3}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} + i \left(\frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6}\right)$$
                                       _________________     /                                        _________________\
                                      /            ____      |                                       /            ____ |
                                     /  243   27*\/ 97       |                               ___    /  243   27*\/ 97  |
                                  3 /   --- + ---------      |              ___            \/ 3 *3 /   --- + --------- |
                  3               \/     4        4          |          3*\/ 3                   \/     4        4     |
x2 = - ------------------------ + ---------------------- + I*|- ------------------------ - ----------------------------|
              _________________             6                |         _________________                6              |
             /            ____                               |        /            ____                                |
            /  243   27*\/ 97                                |       /  243   27*\/ 97                                 |
       2*3 /   --- + ---------                               |  2*3 /   --- + ---------                                |
         \/     4        4                                   \    \/     4        4                                    /
$$x_{2} = - \frac{3}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}} + \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{6} - \frac{3 \sqrt{3}}{2 \sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}\right)$$
                                   _________________
                                  /            ____ 
                                 /  243   27*\/ 97  
                              3 /   --- + --------- 
               3              \/     4        4     
x3 = ---------------------- - ----------------------
          _________________             3           
         /            ____                          
        /  243   27*\/ 97                           
     3 /   --- + ---------                          
     \/     4        4                              
$$x_{3} = - \frac{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}{3} + \frac{3}{\sqrt[3]{\frac{243}{4} + \frac{27 \sqrt{97}}{4}}}$$
x3 = -(243/4 + 27*sqrt(97)/4)^(1/3)/3 + 3/(243/4 + 27*sqrt(97)/4)^(1/3)
Respuesta numérica [src]
x1 = 0.540022156083668 - 1.96846940214568*i
x2 = -1.08004431216734
x3 = 0.540022156083668 + 1.96846940214568*i
x3 = 0.540022156083668 + 1.96846940214568*i
Gráfico
2*x^3+6*x+9=0 la ecuación