Sr Examen

Otras calculadoras

x^3-4*x^2-25*x-100=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  - 4*x  - 25*x - 100 = 0
$$\left(- 25 x + \left(x^{3} - 4 x^{2}\right)\right) - 100 = 0$$
Teorema de Cardano-Vieta
es ecuación cúbica reducida
$$p x^{2} + q x + v + x^{3} = 0$$
donde
$$p = \frac{b}{a}$$
$$p = -4$$
$$q = \frac{c}{a}$$
$$q = -25$$
$$v = \frac{d}{a}$$
$$v = -100$$
Fórmulas de Cardano-Vieta
$$x_{1} + x_{2} + x_{3} = - p$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = q$$
$$x_{1} x_{2} x_{3} = v$$
$$x_{1} + x_{2} + x_{3} = 4$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = -25$$
$$x_{1} x_{2} x_{3} = -100$$
Respuesta rápida [src]
                                             ____________________     /             ____________________                               \
                                            /            _______      |            /            _______                                |
                                           /  1864   5*\/ 12093       |    ___    /  1864   5*\/ 12093                                 |
                                        3 /   ---- + -----------      |  \/ 3 *3 /   ---- + -----------                   ___          |
     4                91                \/     27         9           |        \/     27         9                   91*\/ 3           |
x1 = - - ---------------------------- - ------------------------- + I*|- ------------------------------- + ----------------------------|
     3           ____________________               2                 |                 2                          ____________________|
                /            _______                                  |                                           /            _______ |
               /  1864   5*\/ 12093                                   |                                          /  1864   5*\/ 12093  |
         18*3 /   ---- + -----------                                  |                                    18*3 /   ---- + ----------- |
            \/     27         9                                       \                                       \/     27         9      /
$$x_{1} = - \frac{\sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} - \frac{91}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{4}{3} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} + \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}\right)$$
                                             ____________________     /           ____________________                               \
                                            /            _______      |          /            _______                                |
                                           /  1864   5*\/ 12093       |  ___    /  1864   5*\/ 12093                                 |
                                        3 /   ---- + -----------      |\/ 3 *3 /   ---- + -----------                   ___          |
     4                91                \/     27         9           |      \/     27         9                   91*\/ 3           |
x2 = - - ---------------------------- - ------------------------- + I*|------------------------------- - ----------------------------|
     3           ____________________               2                 |               2                          ____________________|
                /            _______                                  |                                         /            _______ |
               /  1864   5*\/ 12093                                   |                                        /  1864   5*\/ 12093  |
         18*3 /   ---- + -----------                                  |                                  18*3 /   ---- + ----------- |
            \/     27         9                                       \                                     \/     27         9      /
$$x_{2} = - \frac{\sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} - \frac{91}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{4}{3} + i \left(- \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2}\right)$$
              ____________________                              
             /            _______                               
     4      /  1864   5*\/ 12093                  91            
x3 = - + 3 /   ---- + -----------  + ---------------------------
     3   \/     27         9                ____________________
                                           /            _______ 
                                          /  1864   5*\/ 12093  
                                     9*3 /   ---- + ----------- 
                                       \/     27         9      
$$x_{3} = \frac{4}{3} + \frac{91}{9 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}$$
x3 = 4/3 + 91/(9*(5*sqrt(12093)/9 + 1864/27)^(1/3)) + (5*sqrt(12093)/9 + 1864/27)^(1/3)
Suma y producto de raíces [src]
suma
                                        ____________________     /             ____________________                               \                                           ____________________     /           ____________________                               \                                                              
                                       /            _______      |            /            _______                                |                                          /            _______      |          /            _______                                |                                                              
                                      /  1864   5*\/ 12093       |    ___    /  1864   5*\/ 12093                                 |                                         /  1864   5*\/ 12093       |  ___    /  1864   5*\/ 12093                                 |            ____________________                              
                                   3 /   ---- + -----------      |  \/ 3 *3 /   ---- + -----------                   ___          |                                      3 /   ---- + -----------      |\/ 3 *3 /   ---- + -----------                   ___          |           /            _______                               
4                91                \/     27         9           |        \/     27         9                   91*\/ 3           |   4                91                \/     27         9           |      \/     27         9                   91*\/ 3           |   4      /  1864   5*\/ 12093                  91            
- - ---------------------------- - ------------------------- + I*|- ------------------------------- + ----------------------------| + - - ---------------------------- - ------------------------- + I*|------------------------------- - ----------------------------| + - + 3 /   ---- + -----------  + ---------------------------
3           ____________________               2                 |                 2                          ____________________|   3           ____________________               2                 |               2                          ____________________|   3   \/     27         9                ____________________
           /            _______                                  |                                           /            _______ |              /            _______                                  |                                         /            _______ |                                         /            _______ 
          /  1864   5*\/ 12093                                   |                                          /  1864   5*\/ 12093  |             /  1864   5*\/ 12093                                   |                                        /  1864   5*\/ 12093  |                                        /  1864   5*\/ 12093  
    18*3 /   ---- + -----------                                  |                                    18*3 /   ---- + ----------- |       18*3 /   ---- + -----------                                  |                                  18*3 /   ---- + ----------- |                                   9*3 /   ---- + ----------- 
       \/     27         9                                       \                                       \/     27         9      /          \/     27         9                                       \                                     \/     27         9      /                                     \/     27         9      
$$\left(\frac{4}{3} + \frac{91}{9 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}\right) + \left(\left(- \frac{\sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} - \frac{91}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{4}{3} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} + \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}\right)\right) + \left(- \frac{\sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} - \frac{91}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{4}{3} + i \left(- \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2}\right)\right)\right)$$
=
      /           ____________________                               \     /             ____________________                               \
      |          /            _______                                |     |            /            _______                                |
      |  ___    /  1864   5*\/ 12093                                 |     |    ___    /  1864   5*\/ 12093                                 |
      |\/ 3 *3 /   ---- + -----------                   ___          |     |  \/ 3 *3 /   ---- + -----------                   ___          |
      |      \/     27         9                   91*\/ 3           |     |        \/     27         9                   91*\/ 3           |
4 + I*|------------------------------- - ----------------------------| + I*|- ------------------------------- + ----------------------------|
      |               2                          ____________________|     |                 2                          ____________________|
      |                                         /            _______ |     |                                           /            _______ |
      |                                        /  1864   5*\/ 12093  |     |                                          /  1864   5*\/ 12093  |
      |                                  18*3 /   ---- + ----------- |     |                                    18*3 /   ---- + ----------- |
      \                                     \/     27         9      /     \                                       \/     27         9      /
$$4 + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} + \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}\right) + i \left(- \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2}\right)$$
producto
/                                        ____________________     /             ____________________                               \\ /                                        ____________________     /           ____________________                               \\                                                              
|                                       /            _______      |            /            _______                                || |                                       /            _______      |          /            _______                                ||                                                              
|                                      /  1864   5*\/ 12093       |    ___    /  1864   5*\/ 12093                                 || |                                      /  1864   5*\/ 12093       |  ___    /  1864   5*\/ 12093                                 || /         ____________________                              \
|                                   3 /   ---- + -----------      |  \/ 3 *3 /   ---- + -----------                   ___          || |                                   3 /   ---- + -----------      |\/ 3 *3 /   ---- + -----------                   ___          || |        /            _______                               |
|4                91                \/     27         9           |        \/     27         9                   91*\/ 3           || |4                91                \/     27         9           |      \/     27         9                   91*\/ 3           || |4      /  1864   5*\/ 12093                  91            |
|- - ---------------------------- - ------------------------- + I*|- ------------------------------- + ----------------------------||*|- - ---------------------------- - ------------------------- + I*|------------------------------- - ----------------------------||*|- + 3 /   ---- + -----------  + ---------------------------|
|3           ____________________               2                 |                 2                          ____________________|| |3           ____________________               2                 |               2                          ____________________|| |3   \/     27         9                ____________________|
|           /            _______                                  |                                           /            _______ || |           /            _______                                  |                                         /            _______ || |                                      /            _______ |
|          /  1864   5*\/ 12093                                   |                                          /  1864   5*\/ 12093  || |          /  1864   5*\/ 12093                                   |                                        /  1864   5*\/ 12093  || |                                     /  1864   5*\/ 12093  |
|    18*3 /   ---- + -----------                                  |                                    18*3 /   ---- + ----------- || |    18*3 /   ---- + -----------                                  |                                  18*3 /   ---- + ----------- || |                                9*3 /   ---- + ----------- |
\       \/     27         9                                       \                                       \/     27         9      // \       \/     27         9                                       \                                     \/     27         9      // \                                  \/     27         9      /
$$\left(- \frac{\sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} - \frac{91}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{4}{3} + i \left(- \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2}\right)\right) \left(- \frac{\sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} - \frac{91}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \frac{4}{3} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}{2} + \frac{91 \sqrt{3}}{18 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}}\right)\right) \left(\frac{4}{3} + \frac{91}{9 \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}} + \sqrt[3]{\frac{5 \sqrt{12093}}{9} + \frac{1864}{27}}\right)$$
=
100
$$100$$
100
Respuesta numérica [src]
x1 = -2.19805691282578 - 2.66060479565639*i
x2 = -2.19805691282578 + 2.66060479565639*i
x3 = 8.39611382565155
x3 = 8.39611382565155