syms a x y x=sin(a) y=cosh(x) a=linspace(0,2*pi) plot(a,y) 错误在哪里?matlab中，错误提示：Conversion to double from sym is not possible

syms a x y x=sin(a) y=cosh(x) a=linspace(0,2*pi) plot(a,y) 错误在哪里?matlab中，错误提示：Conversion to double from sym is not possible matlab求解方程的时候出现 is not a valid expression or equation.程序如下：syms theta fai psai alpha;syms x y z;eq1='x*x*(1-cos(alpha))+cos(alpha)=cos(theta)*cos(psai)';eq2= 'x*y*(1-cos(alpha))-z*sin(alpha)=cos(psai)*sin(fai)*sin(theta)-s MATLAB符号运算问题运行下面：syms a b x X Y>> k=sym('3');>> z=sym('c*sqrt(d)+y*sin(t)');>> EXPR=a*z*X+(b*x^2+k)*Y;>> symvar(EXPR)得到：ans =[ X,Y,a,b,c,d,t,x,y]这是书上的一个例子.但有一点比较疑惑：符号运算不是都 syms x; >> y=sin(pi*[1:4]'*x); >> plot(x,y) 这个错在那里了?为什么画不出来? 在matlab中如何实现函数的抽样syms x ;y=sin(x)./x;fplot(y,[-10,10]); matlab求积分：y=sin(x),t=y^2/(a+b*y),积分范围（0,pi）,我是这样编写的： syms x a by=sin(x);int(y^2/(b*y+a),0,pi)结果显示：Warning: Explicit integral could not be found. 求高手指点下,错在哪里,我该怎么求这个积分 关于 MATLAB 绘三维图的问题%xyz有以下关系：syms x y z ；a=6;S=a+x;B=sqrt(a^2+x^2+2*a*x*cos(y));H=B/S;c=atan(x*sin(y)/(a+x*cos(y)));z=H*(1-a)*sin(c)/sqrt(S^2+B^2)/(1+sqrt(1-H^2));% 然后我想绘出关于xyz的三维图：x=0:0.1:1;y=- 怎样用MATLAB 或者 maple求解符号方程组怎样用软件实现下列方程组的解啊syms x y R a b >> [a,b]=solve('R*cos(a)-R*cos(a+b)=x','R*sin(a)-R*sin(a+b)=y','a,b') Warning: Explicit solution could not befo y=sin(2x+a)(0 y=sin(2x+a)（0 matlab syms 运行出错>> syms x a b c f=sym('a*x^2+b*x+c')findsym(f,4)y(1)=limit(f,x,1)y(2)=limit(f,1)y(3)=limit(f,a,2)y(4)=limit(f,b,1)yAttempt to execute SCRIPT syms as a function.Error in ==> jixian at 1syms x a b c 请问是为什么呢? matlab >> syms x y;x=linspace(0,2*pi,60);y=(sin(x)*cos(5*x));plot(x,y) 无法出图, 用matlab解含参变量的方程组x,y是需要输入的变量,运行syms x,y,A,C;x=3;y=3;[A,C]=solve('x*sin(A*pi/180)=y*sin(C*pi/180)','A+C=90')报错是y =3A =[ empty sym ]Warning:Explicit solution could not be found.> In solve at 98In jisuann at 为什么MATLAB中符号变量的使用会出错syms x;y=x*sin(x*x);dy=diff(y,x) MATLAB解方程高手进,就是一行程序,syms x y z p3 p33 p333 radius alfa ax ay az A B C ;[x,y,z]=solve('(x-p3)^2+(y-p33)^2+(z-p333)^2=radius^2','(x-ax)^2+(y-ay)^2+(z-az)^2=（2*radius*sin(alfa/2))^2','A*(x-p3)+B*(y-p33)+C*(x-p333)=0','x','y','z Matlab积分报错 syms x y dx dy z t;global e a c;x=a*cos(t);y=a*e*(1-cos(t))*sin(t);dx=diff(x);dy=diff(y);z=sqrt(dx^2+dy^2);int(((a*cos(t)+c)^2+(a*e*(1-cos(t))*sin(t))^2)*z,t,0,pi-acos(c/a));报错为：Error using mupadmexError in MuPAD command:Ei C语言求三角函数f(x,y,z)=sin(x)/(sin(x-y)*sin(x-z))+sin(y)/(sin(y-x)*sin(y-z))+sin(z)/(sin(z-x)*sin(z-y))代码#include #include double fun(double x,double y,double z){double a,b,c,sum;a=sin(x)/(sin(x-y)*sin(x-z));b=sin(y)/(sin(y-x)*sin(y-z));c matlab符号计算问题syms a x;f=a*sin(x)+5;f2=subs(f,{a,x},{2,sym('pi/3')})结果为什么是3^(1/2)+5