Posted by **Ashley** on Sunday, April 7, 2013 at 10:17pm.

Given f(x)=-4+lnx; Find the inverse of f. f^-1=?

- Algebra -
**Reiny**, Sunday, April 7, 2013 at 11:08pm
original:

y = 4 + lnx

inverse:

x = 4 + lny

solving for y

lny = x-4

y = e^(x-4)

f^-1 (x) = e^(x-4)

- Algebra -
**Kendall**, Sunday, April 7, 2013 at 11:23pm
How do you find the domain and range?

- Algebra -
**Reiny**, Sunday, April 7, 2013 at 11:31pm
domain is your choice of x's that you can use in your equation

For logs, one of the main properties is that I can only take the log of a positive number

so for y = 4 + lnx , the domain is x > 0

however, the result of taking such logs results in any real number, so the range is y ∈ R

After taking the inverse of a function, the domain of the original becomes the range of the inverse, and the range of the original becomes the domain of the inverse.

## Answer This Question

## Related Questions

- calculus - Find the minimum distance between the curves y=e^x and y=lnx. Hint: ...
- calculus - sorry to ask a second question so soon, but i'm just not getting this...
- L'Hopital's rule - Find lim x->1+ of [(1/(x-1))-(1/lnx)]. Here is my work...
- Calculus 1 - Find the derivative of y with respect to x. y=(x^6/6)(lnx)-(x^6/36...
- Calculus - Find the minimum distance between the curves y=e^x and y=lnx. Hint: ...
- Calculus - Find the derivatives, dy/dx for the following functions. a. x^2y^4 = ...
- Calculus - what is the limit as h approaches 0 of ((x+h)^pi-x^pi)/h? Multiple ...
- calculus - (a) find the intervals on which f is incrs or decrs. (b) find the ...
- Math - Find the coordinates of the turning point and determine wether it is ...
- Algebra - Given the functions f(x)=x+5/3 and g(x)=1/f^-1(x)+1, find the value ...

More Related Questions