In this book by Buyse (based on Shone) (see picture, I don't get how the author derives the slope of the line g_overdotK(t) = 0 and the slope of the line $g_overdotA(t)=0$.
It seems like the text bounces back and forth between the 'dynamics of the growth rate', e.g. g_overdotA(t)/gA(t) and just the time derivative of the growth rate, namely g_overdotA(t), and uses both interchangeably.
Anyway, by taking the derivative and setting it equal to zero, of the dynamic equation, I get (1-omega)/beta for the slope (nor the 1 result of the other equation). But I don't get why you can work with g_overdotA(t)/gA(t) instead of g_overdotA(t).
What I'm I missing here? Thanks!
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