Step 1: Draw the graph of the sin x

            NOTE: Graph of sin x is a periodic function with period 2π. So we will draw  

                         the graph of y = sin (x) in the interval of [0,2π]. 


Step 2: Draw the graph of the cos x

            NOTE: We know that cos x is periodic with period 2π. That means the

                        graph just repeats forever and ever to the left and right


Step 3: Represent these two graphs in one graph

Step 4: Plot the graph of \cos x - \sin x



Step 5:  Apply the mod to the graph of \cos x - \sin x

             NOTE: Mod means y is always positive so consider x axis as mirror flip the

                     negative values above the x-axis