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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+ |8 j, V1 L8 W2 O& b/ R0 U: q**在这里>> a = sym('a');
6 U8 h5 C* B# }  E8 ^# Q7 _$ q>> b = sym('b');
5 G4 N3 z4 q5 P>> x = sym('x');
9 Z3 v  F- p7 k  {1 o>> y = sym('y');
>> [x,y] = solve('a*x-b*y=1','a*x+b*y=3','x','y')**


Error using solve>getEqns (line 418)
- n: Y% J. p8 I; E+ t7 _/ fList of equations must not be empty.

Error in solve (line 226)
8 s) A: \. |7 p% c[eqns,vars,options] = getEqns(varargin{:});

# E2 e2 ^0 @# Z* ^3 {**>> [x,y] = solve('a*x-b*y=1''a*x+b*y=3','x','y')%第二次尝试修改**

Error using solve>getEqns (line 418)
2 o) j0 r8 b, J4 ^List of equations must not be empty.
Error in solve (line 226)
[eqns,vars,options] = getEqns(varargin{:});
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9 O; }- G) S* j0 {! d- E>> [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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**
↑
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6 ^0 d6 \/ f, b0 bError: 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

0 r% G5 R& Z* J, b9 G2 p9 e2 Zx =

2/a
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( C* a0 i7 Q  P- C$ u3 P5 T- dy =
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1/b

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CCxiaom

这个感觉比较有用