MATLAB，关于solve函数的报错

piday123

我在学习matlab符号运算这一章时尝试把书本的例子输入，发现是有误的，以下是从发现到修改的过程。
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**在这里>> a = sym('a');
>> b = sym('b');
>> x = sym('x');
>> y = sym('y');
% h% R: N, Z, H; F& v>> [x,y] = solve('a*x-b*y=1','a*x+b*y=3','x','y')**

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Error using solve>getEqns (line 418)
1 _5 g3 ]2 y3 c" G7 w3 i; u# \List of equations must not be empty.

Error in solve (line 226)
: B9 l1 b/ i  x0 P, _$ _9 c[eqns,vars,options] = getEqns(varargin{:});
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, F8 h4 o9 s9 R2 m**>> [x,y] = solve('a*x-b*y=1''a*x+b*y=3','x','y')%第二次尝试修改**

! h5 @8 l, k+ }9 X8 xError using solve>getEqns (line 418)
List of equations must not be empty.
; I7 j; i6 l& c7 v8 l- s& cError in solve (line 226)
[eqns,vars,options] = getEqns(varargin{:});
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**

7 y2 Q+ g, D7 i5 j1 _! X>> [x,y] = solve(a*x-b*y=1,a*x+b*y=3,x,y) %第三次尝试修改
[x,y] = solve(a*x-b*y=1,a*x+b*y=3,x,y)
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↑

Error: Incorrect use of ‘=’ operator. To assign a value to a variable, use ‘=’. To compare values for equality, use ‘==’.

>> [x,y] = solve(a*x-b*y== 1,a*x+b*y==3,x,y)%最终成功
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x =

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1/b
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CCxiaom

这个感觉比较有用