Question 278784
working from your equation of:


(62.35)+(-0.46)ln x =61


subtract 62.35 from both sides of this equation to get:


-.46*ln(x) = 61 - 62.35


simplify to get:


-.46*ln(x) = -1.35


divide both sides of this equation by -.46 to get:


ln(x) = -1.35 / -.46 = 2.934782609


use your calculator to find the number whose natural log is 2.934782609 to get:


x = 18.81741195


here's a link to instructions for the TI-84


<a href = "http://education.ti.com/guidebooks/graphing/84p/TI84PlusGuidebook_Part2_EN.pdf" target = "_blank">http://education.ti.com/guidebooks/graphing/84p/TI84PlusGuidebook_Part2_EN.pdf</a>


In my calculator (TI-30), in order to get the natural log of a number, I enter the number and then press the LN key.


If I want to get the number whose natural log is a number, I enter the number and then press the 2D key and then press the LN key.


That's shown as the e^x key in gold letters on top of the LN key.


Looks like you have your LN key to the left of the 4, and looks like you have e^x key being in the 2d function on that same key.


Do the following:


Enter 10 and then hit the LN key.


you should see 2.302585093


hit the 2d LN key.


you should see your 10 come back.


ln(x) and e(x) are inverse functions.


y = ln(x) if and only if x = e^y


your x was 10


your y was 2.302585093


basic definition becomes:


2.302585093 = ln(10) if and only if e^(2.302585093) = 10 which it does.