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x^3-4x^2+7x-3=0 equation

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Numerical solution:

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The solution

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 3      2              
x  - 4*x  + 7*x - 3 = 0
$$\left(7 x + \left(x^{3} - 4 x^{2}\right)\right) - 3 = 0$$
Vieta's Theorem
it is reduced cubic equation
$$p x^{2} + q x + v + x^{3} = 0$$
where
$$p = \frac{b}{a}$$
$$p = -4$$
$$q = \frac{c}{a}$$
$$q = 7$$
$$v = \frac{d}{a}$$
$$v = -3$$
Vieta Formulas
$$x_{1} + x_{2} + x_{3} = - p$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = q$$
$$x_{1} x_{2} x_{3} = v$$
$$x_{1} + x_{2} + x_{3} = 4$$
$$x_{1} x_{2} + x_{1} x_{3} + x_{2} x_{3} = 7$$
$$x_{1} x_{2} x_{3} = -3$$
The graph
Sum and product of roots [src]
sum
                                  _______________     /           _______________                         \                                     _______________     /                                      _______________\            _______________                         
                                 /          ____      |          /          ____                          |                                    /          ____      |                                     /          ____ |           /          ____                          
                                /  43   9*\/ 29       |  ___    /  43   9*\/ 29                           |                                   /  43   9*\/ 29       |                             ___    /  43   9*\/ 29  |          /  43   9*\/ 29                           
                             3 /   -- + --------      |\/ 3 *3 /   -- + --------               ___        |                                3 /   -- + --------      |             ___           \/ 3 *3 /   -- + -------- |       3 /   -- + --------                          
4             5              \/    2       2          |      \/    2       2               5*\/ 3         |   4             5              \/    2       2          |         5*\/ 3                  \/    2       2     |   4   \/    2       2                  5           
- - ---------------------- + -------------------- + I*|-------------------------- + ----------------------| + - - ---------------------- + -------------------- + I*|- ---------------------- - --------------------------| + - - -------------------- + ----------------------
3          _______________            6               |            6                       _______________|   3          _______________            6               |         _______________               6             |   3            3                    _______________
          /          ____                             |                                   /          ____ |             /          ____                             |        /          ____                              |                                    /          ____ 
         /  43   9*\/ 29                              |                                  /  43   9*\/ 29  |            /  43   9*\/ 29                              |       /  43   9*\/ 29                               |                                   /  43   9*\/ 29  
    6*3 /   -- + --------                             |                             6*3 /   -- + -------- |       6*3 /   -- + --------                             |  6*3 /   -- + --------                              |                              3*3 /   -- + -------- 
      \/    2       2                                 \                               \/    2       2     /         \/    2       2                                 \    \/    2       2                                  /                                \/    2       2     
$$\left(- \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{3} + \frac{5}{3 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{4}{3}\right) + \left(\left(- \frac{5}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} + \frac{4}{3} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} - \frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}\right)\right) + \left(- \frac{5}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} + \frac{4}{3} + i \left(\frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6}\right)\right)\right)$$
=
      /                                      _______________\     /           _______________                         \
      |                                     /          ____ |     |          /          ____                          |
      |                             ___    /  43   9*\/ 29  |     |  ___    /  43   9*\/ 29                           |
      |             ___           \/ 3 *3 /   -- + -------- |     |\/ 3 *3 /   -- + --------               ___        |
      |         5*\/ 3                  \/    2       2     |     |      \/    2       2               5*\/ 3         |
4 + I*|- ---------------------- - --------------------------| + I*|-------------------------- + ----------------------|
      |         _______________               6             |     |            6                       _______________|
      |        /          ____                              |     |                                   /          ____ |
      |       /  43   9*\/ 29                               |     |                                  /  43   9*\/ 29  |
      |  6*3 /   -- + --------                              |     |                             6*3 /   -- + -------- |
      \    \/    2       2                                  /     \                               \/    2       2     /
$$4 + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} - \frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}\right) + i \left(\frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6}\right)$$
product
/                                  _______________     /           _______________                         \\ /                                  _______________     /                                      _______________\\ /         _______________                         \
|                                 /          ____      |          /          ____                          || |                                 /          ____      |                                     /          ____ || |        /          ____                          |
|                                /  43   9*\/ 29       |  ___    /  43   9*\/ 29                           || |                                /  43   9*\/ 29       |                             ___    /  43   9*\/ 29  || |       /  43   9*\/ 29                           |
|                             3 /   -- + --------      |\/ 3 *3 /   -- + --------               ___        || |                             3 /   -- + --------      |             ___           \/ 3 *3 /   -- + -------- || |    3 /   -- + --------                          |
|4             5              \/    2       2          |      \/    2       2               5*\/ 3         || |4             5              \/    2       2          |         5*\/ 3                  \/    2       2     || |4   \/    2       2                  5           |
|- - ---------------------- + -------------------- + I*|-------------------------- + ----------------------||*|- - ---------------------- + -------------------- + I*|- ---------------------- - --------------------------||*|- - -------------------- + ----------------------|
|3          _______________            6               |            6                       _______________|| |3          _______________            6               |         _______________               6             || |3            3                    _______________|
|          /          ____                             |                                   /          ____ || |          /          ____                             |        /          ____                              || |                                 /          ____ |
|         /  43   9*\/ 29                              |                                  /  43   9*\/ 29  || |         /  43   9*\/ 29                              |       /  43   9*\/ 29                               || |                                /  43   9*\/ 29  |
|    6*3 /   -- + --------                             |                             6*3 /   -- + -------- || |    6*3 /   -- + --------                             |  6*3 /   -- + --------                              || |                           3*3 /   -- + -------- |
\      \/    2       2                                 \                               \/    2       2     // \      \/    2       2                                 \    \/    2       2                                  // \                             \/    2       2     /
$$\left(- \frac{5}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} + \frac{4}{3} + i \left(\frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6}\right)\right) \left(- \frac{5}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} + \frac{4}{3} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} - \frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}\right)\right) \left(- \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{3} + \frac{5}{3 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{4}{3}\right)$$
=
3
$$3$$
3
Rapid solution [src]
                                       _______________     /           _______________                         \
                                      /          ____      |          /          ____                          |
                                     /  43   9*\/ 29       |  ___    /  43   9*\/ 29                           |
                                  3 /   -- + --------      |\/ 3 *3 /   -- + --------               ___        |
     4             5              \/    2       2          |      \/    2       2               5*\/ 3         |
x1 = - - ---------------------- + -------------------- + I*|-------------------------- + ----------------------|
     3          _______________            6               |            6                       _______________|
               /          ____                             |                                   /          ____ |
              /  43   9*\/ 29                              |                                  /  43   9*\/ 29  |
         6*3 /   -- + --------                             |                             6*3 /   -- + -------- |
           \/    2       2                                 \                               \/    2       2     /
$$x_{1} = - \frac{5}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} + \frac{4}{3} + i \left(\frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6}\right)$$
                                       _______________     /                                      _______________\
                                      /          ____      |                                     /          ____ |
                                     /  43   9*\/ 29       |                             ___    /  43   9*\/ 29  |
                                  3 /   -- + --------      |             ___           \/ 3 *3 /   -- + -------- |
     4             5              \/    2       2          |         5*\/ 3                  \/    2       2     |
x2 = - - ---------------------- + -------------------- + I*|- ---------------------- - --------------------------|
     3          _______________            6               |         _______________               6             |
               /          ____                             |        /          ____                              |
              /  43   9*\/ 29                              |       /  43   9*\/ 29                               |
         6*3 /   -- + --------                             |  6*3 /   -- + --------                              |
           \/    2       2                                 \    \/    2       2                                  /
$$x_{2} = - \frac{5}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} + \frac{4}{3} + i \left(- \frac{\sqrt{3} \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{6} - \frac{5 \sqrt{3}}{6 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}\right)$$
              _______________                         
             /          ____                          
            /  43   9*\/ 29                           
         3 /   -- + --------                          
     4   \/    2       2                  5           
x3 = - - -------------------- + ----------------------
     3            3                    _______________
                                      /          ____ 
                                     /  43   9*\/ 29  
                                3*3 /   -- + -------- 
                                  \/    2       2     
$$x_{3} = - \frac{\sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}}{3} + \frac{5}{3 \sqrt[3]{\frac{43}{2} + \frac{9 \sqrt{29}}{2}}} + \frac{4}{3}$$
x3 = -(43/2 + 9*sqrt(29)/2)^(1/3)/3 + 5/(3*(43/2 + 9*sqrt(29)/2)^(1/3)) + 4/3
Numerical answer [src]
x1 = 1.69632339085132 + 1.43594986410996*i
x2 = 1.69632339085132 - 1.43594986410996*i
x3 = 0.607353218297359
x3 = 0.607353218297359