matlab的内存不足错误

Question

我尝试在matlab上运行以下代码：

syms a c mu epsi real
epsi=10


eq_1=(0.5*pi^2-mu+2*epsi)*a+2*epsi*c-0.25*(3*a^3+3*a^2*c+6*a*c^2);
eq_2=(4.5*pi^2-mu+2*epsi)*c+2*epsi*a-0.25*(a^3+6*a^2*c+3*c^3);
[a_mu  c_mu ]=solve(eq_1,eq_2,a,c)

N_prime=diff(0.5*(a_mu.^2+c_mu.^2),mu)

我收到以下错误：

??? Error using ==> eq
Out of memory. Type HELP MEMORY for your options.

Error in ==> sym.sym>char2sym at 377
if isempty(x) || all(x == ' ') || strcmp(x,'{}')

Error in ==> sym.sym at 95
   S = char2sym(x);

Error in ==> sym.maple at 92
   result = sym(result,'keepijalias');

Error in ==> sym.diff at 50
   R = reshape(maple('map','diff',S(:),x),size(S));

Error in ==> Untitled4 at 10
N_prime=diff(0.5*(a_mu.^2+c_mu.^2),mu)

我该如何解决？