How to plot a function, instead of just values?

function y = fresnelS(f,x,n)

Where the function is defined as follows...

What would you add to the code so that you could plot f?

But instead of getting a list of values I want it to produce a graph.

[Stephen23]

Original function:

function y = fresnelS(f,x,n)
	if mod(n,2) == 1
	error('The number of strips must be even!');
end
h = x./n;
y = f(x);
for k = 1:2:n
	y = y + 4*f(k*h);
end
for k=2:2:n-1
	y = y + 2*f(k*h);
end
y = y.*h/3;
end

Answer 1

[Stephen23]

>> X = linspace(-8,8,500);
>> Y = fresnelS(@(x) sin(x.^2), X, 50);
>> plot(X,Y)