帐号 自动登录 找回密码 密码 欢迎注册
 搜索

# [求助] 初学Matlab解方程组报错

### 马上注册，结交更多好友，享用更多功能，让你轻松玩转社区。

x

>> [u,k]=solve('4+1/(k-u)^2-9/(4-k)^2-1=0','((17^2+u^2)-u^2)*(k-u)^2-u^2=0','u','k')

List of equations must not be empty.

[eqns,vars,options] = getEqns(varargin{:});

>> syms k u
nw=2;
ng=1;
d=17;
x1=4;
z1=3;
h=1;
[k,u]=solve(nw^2/(ng^2)+h^2/ng^2*(k-u)^2-(z1^2/(x1-k)^2)-1,(ng^2*(d^2+u^2)-u^2)*(k-u)^2-(h*u)^2)

k =

(18*root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 1))/17
(18*root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 2))/17
(18*root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 3))/17
(18*root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 4))/17
(16*root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 1))/17
(16*root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 2))/17
(16*root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 3))/17
(16*root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 4))/17

u =

root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 1)
root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 2)
root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 3)
root(z^4 - (68*z^3)/9 + (71383*z^2)/81 - (19652*z)/3 + 1085773/108, z, 4)
root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 1)
root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 2)
root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 3)
root(z^4 - (17*z^3)/2 + (14161*z^2)/16 - (14739*z)/2 + 3257319/256, z, 4)

 很久很久没用MATLAB了，能提供下载链接么，最好是最新版本的，Linux的，

楼主| 发表于 2019-3-18 22:44:00 | 显示全部楼层
 15个G，我下了16个小时

楼主| 发表于 2019-3-18 22:46:28 | 显示全部楼层
 链接: https://pan.baidu.com/s/1idgVVisquz0TPMTFid33nw 提取码: pz74 windows32+64,Matlab2018a

### 点评

 k=vpa(k) 可以得到数值解

 您需要登录后才可以回帖 登录 | 欢迎注册 本版积分规则 回帖后跳转到最后一页

GMT+8, 2020-9-21 14:06 , Processed in 0.196352 second(s), 20 queries .