EXPLANATION
First, let's represent the table with some values of x and y near to the limit:
x y
-0.03 0.66
-0.02 0.65
-0.01 0.64
0.01 0.63
0.02 0.62
0.03 0.62
Now, we need to plot the function:
The limit is 2/π and it does existe because It's defined at x=0