Plotting two equations on matlab

I am trying to plot these two equations on the same graph but it just comes out blank and I can't work out why.

I originally wanted to plot u=3.*exp(t).*[1;1] + exp(-t).*[1;-1] as two seperate lines but I couldn't work out how to do that either

for t = [0:0.1:2];  
    ua= 3.*exp(t)+exp(-t);     
    ub= 3.*exp(t)-exp(-t);    
    plot(t,ua)    
    hold on 
    plot(t,ub)    
end

Answer 1

[Christian Metz]

Just plot it not in a loop. Create t before and then run the code

 t = [0:0.1:2];
  
    ua= 3.*exp(t)+exp(-t);  
   
    ub= 3.*exp(t)-exp(-t);
    
    plot(t,ua)
    
    hold on
 
    plot(t,ub)

[Anna Gilchrist]

thank you

[darova]