A designer is creating various open-top boxes by cutting four equally-sized squares from the corners of a standard sheet of 8.5 inch by 11 inch paper, and then folding up and securing the resulting 'flaps' to be the sides of the box.

Let `x` represent the varying side length of the square cutouts in inches. Let `l,w,` and `h` represent the varying length, width and height of the box (in inches), respectively. Note that the width and length dimensions are such that `w < l` . Let `V` represent the varying volume of the box in cubic inches.

1. Write formulas for length, width, and volume of the box, each in terms of `x` .
   `l=`  
   `w=`  
   `h=`  
   `V=`  
   
   
2. Given the following starting and ending values of `x` , find the change in `x` and the resulting change in `l` .
   

   `x` changes from ...	`Delta x`	`Delta l`
   0 to 0.5 in
   0.5 to 1.5 in
   1 to 4 in

   
   Does `l` change at a constant rate with respect to `x` ? If yes, enter the appropriate value to complete the statement. If no, enter "DNE".
   `Delta l=` `* Delta x` .