How do you find the inverse function #f(x) = 18 + ln(x)#?

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Answer 1 · 2015-10-22T17:13:45

If memory serves me correctly: #" "y=e^(x-18)#
I would recommend you check this against another source!

Given that #f(x)=ln(x) + 18#

Write as #y=ln(x)+18#

Then #ln(x)=y-18#

Consider another way of writing #ln(x)#

This is in fact #e^("something") = x#

In this case #"something" = y-18# giving:

#x=e^(y-18)#

Now all you have to do is exchange the letters #" "x " and " y# giving:

#y=e^(x-18)#