File talk:Drag Curve 2.jpg

Although this curve illustrates that total drag is the sum of induced drag and form drag, it misrepresents that the minimum total or combined drag occurs at the point of interception of induced drag and form drag. Although it is possible for this case to occur, it is an isolated case. The minimum of the sum of two functions or curves occurs where the slope of the sum is zero which occurs when the slopes of the two curves are equal and opposite, not where they intersect. Although the example induced drag curve and the example form drag curve are depicted to have equal slopes at their intersection, this is not normally the case. And, because of this symmetrical depiction, it is possible to mislead the viewer into thinking that you can find the minimum by locating the intersection, which is incorrect.

— Preceding unsigned comment added by 2602:30A:2E73:8930:47C:6751:2E03:A0BD (talk) 18:38, 16 June 2017 (UTC)