"In the fall of 1972, President Nixon announced that the rate of increase of inflation was decreasing. This was the first time a sitting president used the third derivative to advance his case for reelection."
- Civ5
- Civ5
"rate of increase of inflation" (RII) = d inflation / dt
"decreasing rate of increase" = d RII / dt
So the 'rate of increase' of inflation is the second derivative. And to say that the second derivative is decreasing is another way of saying the third derivative is negative
Take that with a grain of salt, I'd welcome any corrections if some one sees fit.
I guess first, does he mean that y, the rate at which x increases is going down by z? or that y is down, but z is not its rate?
And second, if you see inflation here as a derivative or not.
The suggestion seems to be "yes", and that he was playing a game of telling a literal truth that was not however the good news 99.9% of the electorate would take it to be.