You created a second figure object, so the hold call did not apply to it.
You also misspelled ’initial’.
This works:
t = linspace(0,1,1000);
yinitial = 5;
r1 = 5;
y1 = yinitial * exp(r1*t);
figure, plot(y1)
hold on
r2= 10;
y2 = yinitial * exp(r2*t);
plot(y2)
The ‘r1’ plot is barely visible. Use semilogy insatead of plot to make both of them easily seen.
