(x) = log3 (x + 1)
f-1 (x) = ?
(x) = ln(x)
y = log3 ( x + 1) we can write
3^y = x + 1 subtract 1 from both sides
3^y - 1 = x swap x, y
3^x - 1 = y for y, write f-1(x)
f-1(x) = 3^x - 1
y = ln(x) exponentiate both sides
e^y = e^(ln x)
e^y = x swap x, y
e^x = y for y, write f-1(x)
e^x = f-1(x)