Plotting solutions with symbolic variables

I keep getting a syms/sub error for this code. Everything is a constant except for km & Tsp1. How do I solve this error? Very new to MATLAB.

syms Tsp1 km;

xb = (h * P)/ (km * Ac);

mb = sqrt((h*P)/(km*Ac));

neffb = tanh(mb*Lc)/(mb*Lc);

Rthfb = 1/(h*neffb*aff);

Funcb = ((Tw - Ta)*((Li)/(km * Ac))/(Rthfb + ((Li)/(km * Ac)))==(Tw-Tsp1));

Tsp1 = solve(Funcb,Tsp1);

km = linspace(0,100,50);

plot (km,subs(Tsp1,'km',km))

Answer 1

[David Hill]

h=10;P=100;Ac=5;Lc=17;aff=19;Tw=7;Ta=5;Li=11;%have no idea what your constants are
syms Tsp1 km;
xb = (h * P)/ (km * Ac);
mb = sqrt((h*P)/(km*Ac));
neffb = tanh(mb*Lc)/(mb*Lc);
Rthfb = 1/(h*neffb*aff);
Funcb = ((Tw - Ta)*((Li)/(km * Ac))/(Rthfb + ((Li)/(km * Ac)))==(Tw-Tsp1));
Tsp1 = solve(Funcb,Tsp1);
%km = linspace(.1,100,50);
%plot (km,subs(Tsp1,'km',km))
fplot(Tsp1,[0,100])

[Valerie]

Hi David, thank you so much for your response! This helped! Thank you!!