Hi

while looking this picture,

Cost of changes Graph or Progrssing line or Trend of cost of change or Nature of curve, -- Is it correct?

It might be caught by financers or certain analysts.

It is not important for passing exam, but it is worth to discuss for such a reputed standard and institute.

Cost of changes - it is a cumulative graph, and it is true that it will be incremental with the project time passed.

But my point is here as the time pass changes will certainly become lower and lower side. 

 Hence graph will rise but not in accelerating order but in retarding order.