In each of Problems 1-3, find the derivative of the function in part (a). Then find the derivative of the function in part (b) or show that the function in part (b) is the same function as that in part (a).

1. (a) y = ln x - ln (x - 1)

(b) y = ln x / x - 1

2. (a) y = ln (x - 1) + ln (2x + 1)

(b) y = ln [(x - 1)(2x + 1)]

3. (a) y = 1/3 ln (x2 - 1)

(b) y = ln 3 √x2 - 1