Try this:
T=600:10:850;
t = 1;
k1 = 1e7.*exp(-12700./T);
k2 = 5e4.*exp(-10800./T);
k3 = 7e7.*exp(-15000./T);
t=2:2:20;
hold on;
for i=1:numel(t)
Y_B = (k1.*t(i))./(((k2.*t(i))+1).*(1+(t(i).*(k1+k3))));
plot(T,Y_B);
xlabel('Temperature, T / K')
ylabel('Yield of Maleic Anhydride, Y_B')
legend('\tau = 2s','\tau = 4s','\tau = 6s','\tau = 8s','\tau = 10s','\tau = 12s','\tau = 14s','\tau = 16s','\tau = 18s','\tau = 20s')
end
Y_B_fcn = @(t) (k1.*t)./(((k2.*t)+1).*(1+(t.*(k1+k3))));
[Y_B_max1, idx1] = max(Y_B_fcn(1)); % Maximum & Index At ‘t=1’
[Y_B_max20, idx20] = max(Y_B_fcn(20)); % Maximum & Index At ‘t=20’
Y_B_max1 =
0.48894
idx1 =
26
Y_B_max20 =
0.51129
idx20 =
12
