I mentioned this a few years ago, but the PHAK often provides information in the most cryptic, hard to remember way possible.
For example, take temperature - dew point convergence and cloud height. The PHAK gives you
three equations:
1) TDS = T - DP (temp/dew point spread equals temperature - dewpoint)
2) X = TDS / CR (CR is convergence rate)
3) Cloud base = X * 1000
For Pete's sake, write
one equation and simplify it! Cloud base = 1000(T-DP)/CR. CR is 2.5 Celsius, so with Celsius units cloud base = 400(T-DP).
That's it! You can do that math in your head.
Yes, the PHAK explanation is correct, and perhaps illustrates the concept, but what you need to know is 400(T-DP). Even if the authors want to show three equations to illustrate how it works, they should at least refine it to the final (and more useful) simple equation.
And I suspect that if the authors were
pilots they would have done so.