posted by JB .
Verify the function f and g, are inverses of each other by showing that f(g(x))=x and g(f(x))=x Graph the functions.
what's the problem? Just plug and chug:
f(g) = ln(g-1) = ln(1+e^x-1) = ln(e^x) = x
g(f) = 1+e^f = 1 + e^(ln (x-1)) = 1 + x-1 = x
Just keep in mind the definition of a logarithm:
e^lnx = x
ln e^x = x