Tuesday

January 27, 2015

January 27, 2015

Posted by **Michelle** on Tuesday, December 20, 2011 at 8:10pm.

f(x) = 2e^-x + 5

Just looking at this gives me a headache. HELP!

- pre calculus -
**Damon**, Tuesday, December 20, 2011 at 8:31pmx = 2 e^-y + 5

2 e^-y = x-5

e^-y = (x-5)/2

ln e^-y= -y = ln [(x-5)/2]

y = - ln [(x-5)/2]

= - [ ln(x-5) - ln 2 ]

y = ln 2 - ln(x-5)

- pre calculus -
**Reiny**, Tuesday, December 20, 2011 at 8:41pmyour given function is

y = 2e^-x + 5

to form the inverse, interchange the x and y variables, so the inverse is

x = 2e^-y + 5

the inverse graph will be a reflection of the original graph in the line y = x

Pick a few ordered pairs of the original function, e.g.

(0,7), (1, 5.7) , (3, 5.1) , (-1, 10.4 ) , (-5, large) , (5, just a bit over 5)

sketch the first graph

for the inverse, switch the x and y of the ordered pairs, (same as refection in line y = x)

if you want to express your inverse as a function....

x-5 = 2e^-x

take ln of both sides

ln (x-5) = ln2 + ln e^-y

ln(x-5) - ln2 = -ylne , but lne = 1

y = ln2 - ln(x-5)

or

y = ln(2/(x-5) )

**Answer this Question**

**Related Questions**

precalculus - Find the inverse of the function below. Graph the function below ...

College Algebra - Find the inverse of the function below. Graph the function ...

algebra - 1 (a) A function passes through the points (0, -5), (1, 0), (2, 7). ...

Math 3 - Find the inverse of the function f(x) = 5 – e^(x-1). Determine the ...

precalculus - find the inverse of the function, graph the inverse function, ...

pre calculus - Find the inverse of the following function. Find the domain, ...

Pre-calculus - Given the following values for f(t): t : f(t) 3 : -7 6 : 6 9 : 19...

Maths B - (a) What is the inverse of the function y = 3x2 ? (b) On the same set ...

pre-calculus - find the inverse of the following function. Find the domain, ...

Algebra - Myra uses an inverse variation function to model the data for the ...