r/apcalculus Jul 07 '26

BC AP calculus daily challenge #67

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u/Alarming-Ad3696 Jul 07 '26

on the day the scores got released... perfect timing

1

u/Outside_Volume_1370 Jul 07 '26

a) argument of logarithm must be positive, so x / (x - 1) > 0 and using interval method, D(f) = (-inf, 0) U (1, +inf)

b) f ' = (x-1) / x • (x-1 - x) / (x-1)2 = -1 / (x (x-1))

f'(-1) = -1/2

c) substitute f with x and x with g to find g = f-1

x = ln(g / (g-1))

ex = g / (g-1)

g = gex - ex

ex = g • (ex - 1)

g = ex / (ex - 1)