Why is N not being displayed?

My problem: I am trying to find the smallest value of N for which error is less than 10^-4. I am just wondering why N is not being displayed at the end of the code.

N=10;
error=1;
while error<10^-4
	N=N+1;
	sum=0;
	for n=1:N
		y=1/n^2;
		sum=sum+y;
	end
	error=((pi^2)/6)-sum;
	disp(N)
end

Answer 1

[Matt J]

Because the loop condition is never satisfied and therefore nothing within it is ever executed. I think you meant to have,

while error>10^-4

Answer 2

[Image Analyst]

Because you initialized error to 1 so it never enters the while loop at all.

By the way, do not call your variables "error", "sum" or any other built-in function name or you will run into problems.