jacobian calculates the symbolic Jacobian \(df/dx\) of a polynomial \(f(x)\).
J = jacobian(f,x)
With only 1 argument, the differentiation is performed with respect to all involved variables (more precisely, with respect to the variables ecover(depends(f)))
x1 = sdpvar(1,1); x2 = sdpvar(1,1); f = x1^2+5*x2^2; sdisplay(jacobian(f)) ans = '2*x1' '10*x2'
Giving a second argument controls what variables to differentiate with respect to
sdisplay(jacobian(f,x2)) ans = '10*x2'