有关MATLAB求解三元二次方程组的问题？
x1=-226.11;
y1=238.802;
z1=-1577;
x2=223.1317;
y2=201.5533;
z2=-1577;
x3=-277.2719;
y3=-202.0605;
z3=-1577;
syms t1 t2 t3
eq1=(t1*x1-t2*x2)^2+(t1*y1-t2*y2)^2+(t1*z1-t2*z2)^2-532.8689^2;
eq2=(t1*x1-t3*x3)^2+(t1*y1-t3*y3)^2+(t1*z1-t3*z3)^2-532.8689^2;
eq3=(t3*x3-t2*x2)^2+(t3*y3-t2*y2)^2+(t3*z3-t2*z2)^2-753.5904^2;
[t1 t2 t3]=solve(eq1,eq2,eq3,'t1','t2','t3')
楼主我用solve可以解出解来，你参考一下
C1=7.0863;
C2=6.8971;
C3=0.4929;
C4=0.8131;
C5=1.8240;
C6=3.8108;
C7=3.7318;
C8=-2.2238;
C9=1.9905;
C10=1.9087;
C11=0.6778;
syms X1 X2 X3;
exp1 = C1*X1+C4*X2-C5*X3^2-C6*X3-C9;
exp2 = C2*X1+C4*X2-C5*X3^2-C7*X3-C10;
exp3 = C3*X1+C4*X2-C5*X3^2-C8*X3-C11;
[X1,X2,X3] = solve(exp1,exp2,exp3,'X1,X2,X3'); % 直接用 solve 解决
x1 = double(X1)
x2 = double(X2)
x3 = double(X3)
x1 =
0.6280
x2 =
-0.3362
x3 =
0.4687
>> eq1=(18*(2*x - 30))/(5*((y - z)^2 + (x - 15)^2)^(1/2)) + (36*x)/(5*((y - 5)^2 + x^2)^(1/2));
>> eq2=(18*(2*y - 10))/(5*((y - 5)^2 + x^2)^(1/2)) + (18*(2*y - 2*z))/(5*((y - z)^2 + (x - 15)^2)^(1/2)) + 36/5;
>> eq3=(141*(2*z - 16))/(10*((z - 8)^2 + 25)^(1/2)) - (18*(2*y - 2*z))/(5*((y - z)^2 + (x - 15)^2)^(1/2));
>> [x,y,z]=solve(eq1,eq2,eq3,'x','y','z')
经过在matlab7.0中尝试，发现没有问题，可以求解。
x =
1861137696/586981625+2173/1080500*(-3+5*3^(1/2)+30/2173*2173^(1/2))^3-26751/54025*3^(1/2)-160506/117396325*2173^(1/2)+36791/540250*(-3+5*3^(1/2)+30/2173*2173^(1/2))^2
y =
13/2-5/2*3^(1/2)-15/2173*2173^(1/2)
z =
-6519/108050*(-3+5*3^(1/2)+30/2173*2173^(1/2))^2+451757/54025-2173/324150*(-3+5*3^(1/2)+30/2173*2173^(1/2))^3+17834/10805*3^(1/2)+107004/23479265*2173^(1/2)
这里得到的是符号解，转化为数值解；
>> x=subs(x),y=subs(y),z=subs(z)
x =
5.4593
y =
1.8481
z =
7.3564
>>
可是我这边显示BUSY 就是不出答案 怎么办？
我这里很快就算出来了啊，没有那么慢的。显示busy就是在一直计算，你多等一会试试。
有关MATLAB求解三元二次方程组的问题？视频
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国柄备>> [x,y,z]=solve(eq1,eq2,eq3,'x','y','z')经过在matlab7.0中尝试，发现没有问题，可以求解。x = 1861137696\/586981625+2173\/1080500*(-3+5*3^(1\/2)+30\/2173*2173^(1\/2))^3-26751\/54025*3^(1\/2)-160506\/117396325*2173^(1\/2)+36791\/540250*(-3+5*3^(1\/2)+30\/21...
国柄备如要得到数值解，可以这样做 >> fun=@(x)[0.132611776*(x(1)-8.104)+0.895881152*(x(2)-5.017)+0.146428341*(5-5.418),(x(1)-8.104)^2+(x(2)-5.017)^2+(5-5.418)^2];>> [x,h]=fsolve(fun,rand(1,2))执行得到如下结果 从运算结果来看，上述值并不是真正的数值解。
国柄备由于该三元二次方程组有多个解，每组x,y,z各有6个，所以其图像如下所示。实现代码：a=0.2;b0=[0.1:0.1:10];for i=1:length(b0)syms x y z b=b0(i);[x,y,z]=vpasolve(a*(x^2+y^2)+(1-2*a)*x+(a-1)-2*b*z==0,a*y*(x+z)+(1-2*a)*y-b*z==0,a*(y^2...
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