The question asks to overlay the discrete data on the graph, so you need to define markers on the plot of the discrete data (instead of on the graph).
Also, if you are asking a question on this forum, it would be helpful to attach/paste your code instead of a picture of the code.
%define variable t and calculate variable y
t=0:0.001*pi:0.2*pi;
y=50*sin(5*pi*t+pi/3);
%Plotting the graph
plot(t,y)
hold on
%Define values
s=0:0.1:0.6;
x=[43.3 24.6 -43.7 -26.0 44.1 25.3 -43.3];
%Overlaying the graph with given points
plot(s,x,'ro')
%axes and title labels
xlabel("t(seconds)")
ylabel("y")
title("Graph of y versus t")
