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我试图在Matlab2014b环境下数值求解以下方程。但是matlab不输出数值解，而是输出以下

>>solve(1/beta(13,11)*x^(12)*(1-x)^(10)==1.8839,x)
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[1]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[1]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[2]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[2]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[3]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[3]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[4]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[4]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[5]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[5]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[6]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[6]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[7]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[7]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[8]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[8]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[9]
      RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[9]
     RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[10]
     RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[10]
     RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 - (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[11]
     RootOf(z^11 - 5*z^10 + 10*z^9 - 10*z^8 + 5*z^7 - z^6 + (4096*10^(1/2)*3342794185613871913^(1/2))/66540040320887625, z)[11]

另一方面，我没有用 Wolframmath 求解方程的问题。我想知道是什么导致了这个问题，值得注意的是方程确实有复杂的解，但我只对 0 和 1 之间的解感兴趣。

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1 回答 1

1

我刚才遇到了同样的问题，我想我已经找到了解决方案。

从我得到的信息来看，MATLAB 有时会这样做以简单地表示分析解决方案。要评估解决方案，只需调用vpa函数。这是一个最小的复制和解决方案。

    syms x
    solve(x^5 + x + 7)

结果会像

    ans =

     RootOf(z^5 + z + 7, z)[1]
     RootOf(z^5 + z + 7, z)[2]
     RootOf(z^5 + z + 7, z)[3]
     RootOf(z^5 + z + 7, z)[4]
     RootOf(z^5 + z + 7, z)[5]

只需尝试

    vpa(ans)

然后数值结果将显示：

    ans =

                                           -1.4108138510595771319852918753499
     - 0.5084694089730227818822736708423 + 1.3686164883298987835863274173391i
     - 0.5084694089730227818822736708423 - 1.3686164883298987835863274173391i
      1.2138763345028113478749196085173 + 0.92418811092205120320563065825557i
      1.2138763345028113478749196085173 - 0.92418811092205120320563065825557i

有关详细信息，请参阅 MATLAB 文档：

http://au.mathworks.com/help/symbolic/solve.html#zmw57dd0e111869

于 2015-10-19T11:12:48.293 回答