初学者求教！！！

[M.J_Victor]

我刚接触MATLAB,想问一下这几个算式用MATLAB怎么做？谢谢！！！.
f=[a,t^3;t*cos(x),log(x)]，求df/dx,d^2f/dt^2,d^2f/dtdx.
f(x1,x2)=[x1*exp(x2);x2;cos(x1)*sin(x2)]的Jacobian矩阵[af1/ax1,af2/ax2;af2/ax1,af2/ax2;af3/ax1,af3/ax2].
f(x)=sin/x/,求fx(0)',fx(x)'.

[TTT_IOU]

syms a t x x1 x2
f=[a,t^3;t*cos(x),log(x)];
fx12=[x1*exp(x2);x2;cos(x1)*sin(x2)];
dfx=diff(f,x);
dft2=diff(f,t,2);
dftx=diff(dfx,t);
jx12=jacobian(fx12,[x1,x2]);
fx=sin(abs(x));
fx_x=diff(fx);
望有帮助！！！