如何用matlab解出一个未知数的代数表达式 matlab解带未知数的行列式
\u83dc\u9e1f\u95ee\u9898~\u7528MATLAB\u600e\u4e48\u628a\u4e00\u4e2a\u672a\u77e5\u6570\u8868\u8fbe\u5f0f\u4ee3\u5165\u522b\u7684\u5f0f\u5b50\u6c42\u7ed3\u679c\uff1f\u697c\u4e0a\u7684\u5199\u6cd5\u4e0d\u59a5\u3002\u6309\u7167\u4e0a\u9762\u7684\u8bed\u53e5\u987a\u5e8f\uff0c\u6700\u540e\u4e00\u6b65\u6839\u672c\u5c31\u4e0d\u9700\u8981subs\uff1a
>> syms t;>> x=30+t;>> y=3*x+5*t y = 90+8*t
\u6309\u7167\u697c\u4e3b\u7684\u8981\u6c42\uff0c\u6211\u8ba4\u4e3a\u4ee3\u7801\u5e94\u8be5\u662f\u8fd9\u6837\u7684\uff1a
>> syms x t>> y=3*x+5*t y = 3*x+5*t >> y=subs(y,x,30+t) y = 90+8*t
syms x
A=[5-x^2 8 0 0; 2 3-5*x^2 2 9; 8 0 7-12*x^2 8;2 6 8 9-7*x^2];
f=det(A);
ezplot(f,[-3 3]); \u5224\u65ad\u96f6\u70b9\u503c\u7684\u8303\u56f4
fun=inline(f,'x');
fzero(fun,[-4,-2]),fzero(fun,[2,4]);
ans = -2.4470
ans = 2.4470
>> solve('0.15*D*x=(0.1*0.7*(1-(x)/0.5)/(0.02+0.1-(x)/0.5)+0.02)*x','x')
ans =
solve([0.15*x*D == x*((0.14*x - 0.07)/(2.0*x - 0.12) + 0.02)], [x])
>> x=solve([0.15*x*D == x*((0.14*x - 0.07)/(2.0*x - 0.12) + 0.02)], [x])
x =
0
(45*D - 181)/(750*D - 450)
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绛旓細>> solve('0.15*D*x=(0.1*0.7*(1-(x)/0.5)/(0.02+0.1-(x)/0.5)+0.02)*x','x')ans = solve([0.15*x*D == x*((0.14*x - 0.07)/(2.0*x - 0.12) + 0.02)], [x])>> x=solve([0.15*x*D == x*((0.14*x - 0.07)/(2.0*x - 0.12) ...
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