作者saniao (saniao)
看板MATLAB
标题[讨论] solve方程组
时间Tue May 5 21:14:12 2015
请问一下
我今天有3个未知数a,b,c待求定
亦有三个方程式eq1,eq2,eq3
我使用symbolic进行解方程组
为什麽每个解都是8x1 syms呢
小弟数学不好请见谅
code如下
syms a b c
eq1=(1+a^2-b^2-c^2)/(1+a^2+b^2+c^2)-0.99768250;
eq2=(1-a^2+b^2-c^2)/(1+a^2+b^2+c^2)-0.75500072;
eq3=(1-a^2-b^2+c^2)/(1+a^2+b^2+c^2)-0.75731587;
[a,b,c]=solve(eq1,eq2,eq3,'a','b','c')
------
结果如下
a =
-8638450155872395594504574183690^(1/2)/7903815296897390
8638450155872395594504574183690^(1/2)/7903815296897390
-8638450155872395594504574183690^(1/2)/7903815296897390
8638450155872395594504574183690^(1/2)/7903815296897390
-8638450155872395594504574183690^(1/2)/7903815296897390
8638450155872395594504574183690^(1/2)/7903815296897390
-8638450155872395594504574183690^(1/2)/7903815296897390
8638450155872395594504574183690^(1/2)/7903815296897390
b =
-10456213264794931385910795^(1/2)/3951907648448695
-10456213264794931385910795^(1/2)/3951907648448695
10456213264794931385910795^(1/2)/3951907648448695
10456213264794931385910795^(1/2)/3951907648448695
-10456213264794931385910795^(1/2)/3951907648448695
-10456213264794931385910795^(1/2)/3951907648448695
10456213264794931385910795^(1/2)/3951907648448695
10456213264794931385910795^(1/2)/395190764844869
c =
-82451023629991619035344171910^(1/2)/7903815296897390
-82451023629991619035344171910^(1/2)/7903815296897390
-82451023629991619035344171910^(1/2)/7903815296897390
-82451023629991619035344171910^(1/2)/7903815296897390
82451023629991619035344171910^(1/2)/7903815296897390
82451023629991619035344171910^(1/2)/7903815296897390
82451023629991619035344171910^(1/2)/7903815296897390
82451023629991619035344171910^(1/2)/7903815296897390
还请板上高手指点迷津
是我用的function有错吗
还是正解就是这样= _=
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1F：→ Joshiki727: 2^3种解 abc的正/负组合……吗 05/05 21:42
2F：→ saniao: 那哪一组才是正确的>< 05/05 22:28
3F：→ celestialgod: 你可以double(a)看实数值 05/05 23:12
4F：→ ejialan: 非线性方程有可能有多解 这题A=a^2,B=b^2,C=c^2可线性化 05/06 10:55
5F：→ ejialan: 开根号要取正负所以有2^3组解 如果abc没有限制就都是解 05/06 10:56
6F：→ ejialan: 有限制 例如a>0,b>0,c>0 解数目就会变少 05/06 10:58
7F：→ saniao: 好的 我知道了 感谢J大 C大 E大详细解说 05/06 13:32