MATLAB: How to get this graph

graph

I want to get the graph of n and x(n) on x(n+1)=2.5*x(n)*(1-x(n)), where x(1)=0.9

I wrote

x(1)=0.9;

for n = 1:100,

x(n+1)=x(n)*(1-x(n))*2.5

plot (x(n),n)

end

and my plot is empty

Try this

x(1)=0.9;
for n = 1:100
x(n+1)=x(n)*(1-x(n))*2.5;
end
plot(x)

In your code, you are just plotting one point at a time and then overwriting it with a new plot statement.

n=.05:.01:.3;
x_n=(n.^2-1)./(n.^2);
plot(n,x_n);