matlab里面S_sym=sym('sin(-3*t)*exp(-t)');中sym是什么意思,不加可以吗?

matlab里面S_sym=sym('sin(-3*t)*exp(-t)');中sym是什么意思,不加可以吗? matlab符号计算出错本人在matlab7中运行书本中如下符号计算例题clearsyms xg=sym('cos(x+sin(y(x))')dgdx=diff(g,x)matlab7显示出错如下：Error using ==> sym.sym>char2symNot a valid symbolic expression.Error in ==> sym.sym at 92S matlab运行syms x；s=solve(x^3+cos(x)) 为什么结果总是[ empty sym ]啊, matlab 中,syms x 是不是相当于x=sym('x') 用matlab解题出现y = [ empty sym ] 为什么 Matlab s=solve('x(e^(1/(y*26))-1)=1','x(e^(1.5/(y*26))-1)=80');s.x,s.yError using ==> mupadmexError in MuPAD command:cannot differentiate equation [numeric::fsolve]Error in ==> sym.sym>sym.mupadmexnout at 2018out = mupadmex(fcn,args{:});Error in ==> 求解四元二次方程,用matlab用下列命令求解s=solve('x-a=-0.00352888888888888*x*(b-y)','(y-b)^2+(x-a)^2=64','y=-0.00176444444444444*x^2','b=-0.30573068145866*a-19.125454495657');ss.xs.ys.as.b结果为：s = a:[6x1 sym]b:[6x1 sym]x:[6x1 sym matlab Error using ==> sym.mpowerError using ==> sym.mpowerMatrix must be square.我没用什么矩阵饿? 在matlab中 a=sym('2'); a=sym(2); 区别在哪,意义分别是什么 A=sym(pascal(2)); 意义是啥a=sym('2');a=sym(2);区别在哪,意义分别是什么A=sym(pascal(2));意义是啥 Matlab画不出波形,f(t)=sin(2*pi*sym('f0')*t)-alpha*sin(2*pi*sym('f0')*t)*[u*(t-sym('t1'))-u*(t-sym('t2'))];sym('f0')=50,sym('t1')=0.04,sym('t2')=0.1,alpha=0.2;plot(f(t),t);grid on这个是命令里的Error in ==> one at 1f(t)=sin(2*pi*sym('f0')*t matlab中 定义 p=sym('[p1, p2]') 是 什么意思?谢谢. Matlab sym的指令意义和格式 matlab中 [2x1 sym] 是什么意思啊 matlab里面Conversion to double from sym is not possible.怎么回事啊?求大神y=dsolve('D2y+y=sin(t) * cos(30)','t') plot(y)结果提示Conversion to double from sym is not possible. 这是怎么回事 求大神 matlab解方程式>> syms x>> s=solve('(3.4-3.2)/(3.2-2.3)=(0.85-x)/(x-0.65)');>> x=s.x用上述命令求解x,怎么提示如下内容：Error using ==> subsrefNo appropriate method,property,or field x for class sym.Error in ==> sym.subsref at 17y = matlab 程序出错syms a b c;M1=sym('kiu');M2=sym('kog');M3=sym('lou');syms_matrix=syms_matrix=[a b c;M1,M2,M3;int2str([2 3 5])] matlab solve函数解方程错在哪里输入：syms xf=sym('-x^3+x^2-1=0')v=solve(f)w=double(v)结果：Attempt to execute SCRIPT solve as a function.Error in ==> sym.solve at 49[varargout{1:max(1,nargout)}] = solve(S{:});Error in ==> solve at 3v=so matlab 命令solve 出错sym xsolve('-x+sinh(0.3466*log2((1+x)/(1-x)))=0',x) Error using ==> solveUnable to find closed form solution.Error in ==> sym.solve at 49[varargout{1:max(1,nargout)}] = solve(S{:});