Will try my best, see if you can make sense of this. Let me just talk about Total Drag to keep things simple.
Imagine the Total Drag Curve as an italicized upper case letter J. If you draw the hook part of the J at about an inch of distance from the vertical axis, the distance of the bottom of the J to the horizontal axis is about 1.5 of that. The vertical axis is drag (pounds as unit, for example) and the horizontal is speed.
Typical Vs (Stall Speed) is also about an inch from zero (along the horizontal, of course). If you draw a line upwards from Vs, it will intersect with the top part of the hook of the curve (or letter J). From there on, any incremental increase in speed (movement to the right along the horizontal or speed axis) results in lesser total drag. Makes sense so far?
This happens up to the point where speed intersects the bottom portion of the letter J, where it then begins going up again.
You familiar with Improved Climb computations? Where field length is not limiting, the take-off chart tries to give you a higher speed than usual to get you to that low point in the drag curve.
My 2 cents' worth. Cheers
