Verified Answer :

Hagrid

The correct answer for this question is this one:

Starting with ln[(2X - 1)/(X - 1)] = t, solve for X in terms of t: 

(2X - 1)/(X - 1) = e^t ----> 

2X - 1 = (X - 1)e^t ----> 

2X - Xe^t = 1 - e^t -----> 

X(2 - e^t) = 1 - e^t -----> 

X = (1 - e^t)/(2 - e^t) = (e^t - 1)/(e^t - 2). 

Now differentiate ln[(2X - 1)/(X - 1)] = ln(2X - 1) - ln(X - 1) = t implicitly: 

(2/(2X - 1))dX/dt - (1/(X - 1))dX/dt = 1

dX/dt((2(X - 1) - (2X - 1)) / ((2X - 1)(X - 1))) = 1

dX/dt(-1) = (2X - 1)(X - 1)

dX/dt = (X - 1)(1 - 2X).
Hope this helps you answer your question.

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