matlab求解含有字母的非线性方程组syms x1 x2 x3 x4 x5 x6 x20 D;f1 =x1*(67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-D);f2 =D*(x20-x2)-(11/5+3350/41*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)+1429/50*x2/(x2+1143/100))*x1;f3 =(-269/100+4535

matlab求解含有字母的非线性方程组syms x1 x2 x3 x4 x5 x6 x20 D;f1 =x1*(67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-D);f2 =D*(x20-x2)-(11/5+3350/41*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)+1429/50*x2/(x2+1143/100))*x1;f3 =(-269/100+4535
matlab求解含有字母的非线性方程组
syms x1 x2 x3 x4 x5 x6 x20 D;
f1 =x1*(67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-D);
f2 =D*(x20-x2)-(11/5+3350/41*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)+1429/50*x2/(x2+1143/100))*x1;
f3 =(-269/100+453523/10000*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)+2659/100*x2/(x2+31/2))*x1-D*x3;
f4 =54664/151*x2/(x2+67/50)+900000017/9800000001*x2-900000017/9800000001*x4-2200/151-3350000/6191*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-28580/151*x2/(x2+1143/100)-67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)*x4;
f5 =8721/500*(14/5-23651/10000*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-87/100*x2/(x2+241/100))*x4/(53/100+1444899991113/2222500015550*x5+x4)-11067/500*(58/25-12529/10000*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-69/50*x2/(x2+27/20))*x5/(7/50+x5*(1+500/209*x5))-67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)*x5;
f6 =11067/500*(58/25-12529/10000*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-69/50*x2/(x2+27/20))*x5/(7/50+x5*(1+500/209*x5))-25137/1000*x6+25137/1000*x3-67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)*x6;
[x1 x2 x3 x4 x5 x6]=solve(f1,f2,f3,f4,f5,f6,'x1','x2','x3','x4','x5','x6');
解不出来

matlab求解含有字母的非线性方程组syms x1 x2 x3 x4 x5 x6 x20 D;f1 =x1*(67/100*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)-D);f2 =D*(x20-x2)-(11/5+3350/41*x2/(x2+7/25)*(1-1/2039*x2)*(1-2/1879*x3)+1429/50*x2/(x2+1143/100))*x1;f3 =(-269/100+4535
我直接拷进去并没有报错,
S=solve('d=k*(d/tan(a)-r*n/num)+h','sin(a)=asin(n*sin(acot(k)))','a','k')
S =
a:[2x1 sym]
k:[2x1 sym]
a
a =
atan(k*d*num/(d*num+k*r*n-h*num))
k
k =
(-sin(sin(a))^2+n^2)^(1/2)/sin(sin(a))
-(-sin(sin(a))^2+n^2)^(1/2)/sin(sin(a))
你是不是没有清除变量,或者是matlab 2008a版的,那个版本有些函数有改动,可以试一下
[a,k]=solve('d=k*(d/tan(a)-r*n/num)+h','sin(a)=asin(n*sin(acot(k)))')