Question 56055
Your graph would just be a horizontal line at 0. the two 2s would cancel out and you would be left with f(x)=0. Since there is no "x", there can't be a slope. 
I hope this is what your asking about.
The red line is what it would like like if it were f(x)=x
The green line is your graph.
{{{graph(300,200,-5,5,-5,5,x,0)}}}