inflation is a rate of increase first derivative)

no, "the rate of increase is decreasing" is a second derivative already

dxdeez nuts.

No shitting. the inflation of the inflation of the inflation has decreased.

First Derivative: This is the inflation rate itself (the change in price levels over time). Second Derivative: This would represent the acceleration of inflation, or how the inflation rate is changing over time. If this is positive, inflation is accelerating; if negative, inflation is decelerating. Third Derivative: This would represent the rate of change of the acceleration of inflation. So, if you say "the rate of increase in inflation is decreasing," it could imply that the acceleration of inflation is decreasing, which would indeed relate to the third derivative.

So inflation is still increasing but it just doesn't increase as fast as it used to – great!