Coding a First/Second Derivative Test in MATLAB?

This is my attempt at coding first/second derivative tests. I seem to be getting nothing out of my if-statement though. Any ideas/help would be greatly appreciated! Thank you all of course in advance

clc; clear; close all;

syms w tsig teps w1 w2

del = atan(w.*(tsig-teps)./(1+(w.^2.*(tsig.*teps))));

w_max = (teps*tsig).^(-1/2);

derv_del = diff(del,w)

derv_del0(w,tsig,teps) = derv_del;

derv_del_wmax = derv_del0(w_max,tsig,teps)

%First Derivative Test

lt(w1,w_max)

gt(w2,w_max)

if (isAlways(gt(derv_del0(w1,tsig,teps),0)) && isAlways(lt(derv_del0(w2,tsig,teps),0)))

disp('del has a maximum at the given w')

end

if (isAlways(lt(derv_del0(w1,tsig,teps),0)) && isAlways(gt(derv_del0(w2,tsig,teps),0)))

disp('del has a minimum at the given w')

end

%Second Derivative Test

derv_del02(w,tsig,teps) = diff(diff(derv_del))

derv_del_wmax2 = derv_del02(w_max,tsig,teps)

if (isAlways(lt(derv_del_wmax2,0)))

disp('del has a maximum at the given w')

end

if (isAlways(gt(derv_del_wmax2,0)))

disp('del has a minimum at the given w')

end