关于这种出错的问题，如何解决？(语言-matlab)

x=solve('exp(-3x)sin(4x+2)+4(exp(-0.5x)cos(2x)-0.5')
Error using solve>processString (line 354)
' exp(-3x)sin(4x+2)+4*(exp(-0.5*x)cos(2x)-0.5 ' is not a valid expression or equation.

Error in solve>getEqns (line 284)
eqns = processString(eqns, v, vc);

Error in solve (line 160)
[eqns,vars,options] = getEqns(varargin{:});

符号表达式不能你那样些，比如3与x之间都是要*乘号的

你好，现在字符串要转化成符号

x=solve(str2sym('exp(-3*x)*sin(4*x+2)+4*(exp(-0.5*x)*cos(2*x)-0.5)'))

结果：

 
x =
 
0.42290069284152102283948443313377