求直线和曲线交点，离散或连续曲线。

请问求直线y=x和一条曲线y=(-1.477e-5)x^3+0.05013x^2-0.001057*x-4.987在x大于10以后的交点怎么求呢，谢谢？

我写了一下程序，但是报错，有没有什么更好的程序，可以使x的范围连续

clear;
clc;
syms x y
x=10:0.1:60
f1=x-y;
f2=(-1.477e-5)*x^3+0.05013*x^2-0.001057*x-4.987-y;
   [x,y]=solve(f1,f2);
   x=double(x)
   y=double(y)
   plot(x,y)

Answer 1

[kahine]

这个问题很简单啊，既然你都知道用solve函数，你看看这个函数的帮助文件，举的例子就是sin(x) == x^2 - 1；而且还带绘图，带求解具体的值，你换成你的函数不就得了，多看看帮助才能成长

syms x
eqn = x == (-1.477e-5)*x^3+0.05013*x^2-0.001057*x-4.987;
S = solve(eqn,x);
V = vpasolve(eqn,x); %有三个解分别为
% -4.127550240554986891034769540832
% 24.245503424174890648425950143157
% 3373.9240237967458874167982732993
fplot([lhs(eqn) rhs(eqn)], [0 3500])
hold on
plot(V(V>10),V(V>10),'ro')

[Roderick]

感谢您提供的解决方案和建议！我会仔细阅读solve函数的帮助文件，并尝试将您给出的例子应用到我的函数上。再次感谢您的帮助！

[DGM]

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