跪求用Matlab解带指数的三元方程组 求matlab解三元方程组，最好能把命令行列出来
\u6c42\u9ad8\u624b\u7528matlab\u89e3\u4e00\u4e2a\u4e09\u5143\u7684\u65b9\u7a0b\u7ec4\u65b9\u7a0b\u65e0\u89e3\u3002\u53ef\u4ee5\u5f88\u7b80\u5355\u5730\u753b\u51fa\u4e24\u4e2a\u65b9\u7a0b\u7684\u66f2\u7ebf\u6765\uff1a
ezplot('-0.050+0.015+0.070-2.*(d.*0.0215).^0.5-2.*(p.*0.0504).^0.5',[-0.02 0.02])
hold on
ezplot('-0.015+d+p',[-0.02 0.02])
\u7531\u56fe\u53ef\u89c1\uff0c\u4e24\u6761\u7ebf\u65e0\u4ea4\u70b9\uff0c\u4e5f\u5c31\u610f\u5473\u7740\u65b9\u7a0b\u7ec4\u65e0\u89e3\u3002
\u6216\u8005\u6362\u53e6\u4e00\u79cd\u65b9\u5f0f\u6765\u5206\u6790\uff1a\u628a\u65b9\u7a0b1\u4ee3\u5165\u65b9\u7a0b2\uff1a
syms d p
eq1=-0.015+d+p;
eq2=-0.050+0.015+0.070-2.*(d.*0.0215).^0.5-2.*(p.*0.0504).^0.5;
d=solve(eq1,d)
eq=subs(eq2,d,d)\u5f97\u5230\u65b9\u7a0b\uff1a
>> eq=subs(eq2,d,d)
eq =
7/200 - 2*(129/400000 - (43*p)/2000)^(1/2) - 2*((63*p)/1250)^(1/2)\u65b9\u7a0b\u4e2d\u4e24\u4e2a\u5305\u542bp\u7684\u9879\u90fd\u8981\u8fdb\u884c\u5f00\u5e73\u65b9\uff0c\u5e94\u8be5\u5927\u4e8e0\uff0c\u5373\uff1a
(63*p)/1250
>=
0
129/400000
-
(43*p)/2000
>=
0
\u8054\u7acb\u89e3\u5f97
0<=p<=0.015\uff0c\u753b\u51fa\u8be5\u65b9\u7a0b\u7684\u66f2\u7ebf\u5982\u4e0b\uff1a
\u4e0d\u53ef\u80fd\u4e0e0\u8f74\u76f8\u4ea4\uff0c\u4e5f\u5373\u65b9\u7a0b\u65e0\u89e3\u3002
\u6c42matlab\u89e3\u6b64\u4e09\u5143\u65b9\u7a0b\u7ec4\uff0c\u53ef\u4ee5\u8003\u8651\u7528fsove\uff08\uff09\u51fd\u6570\u6765\u6c42\u89e3\u3002
1\u3001\u9996\u5148\u81ea\u5b9a\u4e49\u51fd\u6570fun(x)
fun=@(x)[11*cos(x(2))+x(1)-350,cos(x(3).*x(1))+sin(x(2)),1/tan(x(2))+x(3)*11.*sin(x(3).*x(1))]; %x=x(1),y=x(2),z=x(3)
2\u3001\u7136\u540e\u7528fsove\uff08\uff09\u51fd\u6570\u6c42\u89e3
x0=[300 2 -0.01], [x,h]=fsolve(fun,x0)
3\u3001\u6c42\u89e3\u7ed3\u679c
x\u2248350.01\uff1by\u22481.5713\uff1bz\u22480.044877
4\u3001\u6c42\u89e3\u754c\u9762
用solve（）函数，求解就ok了.
v1=53.56;v2=24.46;v3=10.16;T1=323.13;T2=343.13;T3=373.13;
syms A B m0
s=solve(log10(v1+A)-B+m0*log10(T1),log10(v2+A)-B+m0*log10(T2),log10(v3+A)-B+m0*log10(T3));
s.A,s.A,B.m0
运行结果如下
先新建一个函数
function F = fun1( x )
v1=53.56;
v2=24.46;
v3=10.16;
T1=323.13;
T2=343.13;
T3=373.13;
F=[log10(v1+x(1))-x(2)+x(3)*log10(T1);
log10(v2+x(1))-x(2)+x(3)*log10(T2);
log10(v3+x(1))-x(2)+x(3)*log10(T3)];
end
再重新建个脚本
clc
x0=[1 -10 1];
options=optimoptions('fsolve','Display','iter','TolFun',1e-50,'TolX',1e-50);
[x,fval,~,output,~] = fsolve(@fun1,x0,options);
A=x(1)
B=x(2)
m0=x(3)
x0是初值，初值不同解可能不同（局部收敛）
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绛旓細鍙互姹傝В锛屽彲鑳戒綘娌℃湁瀹屽叏鐞嗚В濡備綍浣跨敤solve锛堬級鍑芥暟銆傚浜庝綘鐨勬柟绋嬶紝搴旇杩欐牱鏉ユ眰銆俿yms x a=-0.0008366;b=0.008461;c=10.46;d=-9.462e-005;x=solve(10.450-( a*exp(b*x) + c*exp(d*x)))姹傝В缁撴灉 x=9.1941461897150424695683645683291 灏唜鍊间唬鍏x = a*exp(b*x) + c*exp(d*x...
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绛旓細x^(1/3)鍗冲彲銆matlab涓眰骞虫柟鏍癸紙浜屾鏂规牴锛夌敤sqrt锛屼絾娌℃湁涓撻棬琛ㄧず涓夋鏂规牴鐨勫嚱鏁般傝绠椾笁娆℃柟鏍圭瓑浠蜂簬璁＄畻鏌愪釜鏁鐨勪笁鍒嗕箣涓娆℃柟銆傛墍浠ュ彲浠ヤ娇鐢╬ower(x,1/n)鐨勬柟娉(琛ㄧず寮n娆℃柟鏍)銆備妇渚嬶細>> x=4 x = 4 >> power(x,1/3)ans = 1.5874 >> 4^(1/3)ans = 1.5874 ...
绛旓細鐩存帴鍦ㄥご鏂囦欢閲屽姞#include<math.h> 濡備笅鍑芥暟鍒嗗埆杩斿洖杈撳叆鍙傛暟x鐨鎸囨暟銆佸鏁般佸箙鍊煎拰鐩歌銆俧unction [a, b, c, d] = fun(x)a = exp(x);b = log(x);c = abs(x);d = angle(x);
绛旓細鍦∕ATLAB缂栫▼涓紝鎸囨暟鍑芥暟鐨勮〃绀洪潪甯哥洿瑙傘傚鏋滀綘鎯宠璁＄畻e鐨勪换鎰忔骞傦紝鍙互鐩存帴浣跨敤`exp(n)`鍑芥暟锛屽叾涓璶鏄綘鎯宠鐨勬寚鏁般傝繖涓嚱鏁颁笓闂ㄧ敤浜庤〃绀轰互鑷劧甯告暟e涓哄簳鐨勫箓杩愮畻銆傚鏋滀綘闇瑕佽绠楀叾浠栧簳鏁扮殑鎸囨暟锛屾瘮濡俛鐨剎娆℃柟锛孧ATLAB鍚屾牱鎻愪緵浜嗙浉搴旂殑鍑芥暟锛屽嵆`a^x`銆傝繖涓搷浣滅`^`鐢ㄤ簬琛ㄧず浠讳綍瀹炴暟鎴栧鏁板簳鏁扮殑...
绛旓細exp(m)鏄煩闃典腑姣忎釜鍏冪礌鐨鎸囨暟锛岃宔xm鐨勬剰涔夎繙涓嶆槸杩欐牱銆傚睍寮(x)灏嗙壒寰佸悜閲忕煩闃典箻浠xp(鐗瑰緛鍊煎瑙掔煩闃)涔樹互inv(鐗瑰緛鍚戦噺)[v,d]=eig(x))鎵╁睍(x)=v*diag(渚嬪a(diag(d))/v.=1,2,0>>exp(a)ans=2.7183 7.3891 7.381.0000鎵╁睍(a)ans=8.1286 6.1828 6.1828 5.0372 ...
绛旓細He鏄父鏁板悧濡傛灉鏄殑璇濇垜鐨勬柟娉曞涓嬶紙鍥犱负娌℃湁鍏蜂綋鏁版嵁锛屾垜灏遍殢渚跨粰浜嗕竴涓婯銆乀鍜孒e鐨勫弬鏁帮紝浣犲彲浠ユ牴鎹疄闄呮儏鍐典慨鏀癸級銆備富绋嬪簭 clc;clear K = [1;2;3;4];T = [1;4;2;3];He = 1;Ct0 = rand(numel(K)+1,1);options = optimset('TolFun',1e-16); % 绮惧害瑕佹眰 Ct = fsolve(@(...
