
(a)
![f'(x) = \frac{d}{dx}[\frac{lnx}{x}]](https://tex.z-dn.net/?f=f%27%28x%29%20%3D%20%5Cfrac%7Bd%7D%7Bdx%7D%5B%5Cfrac%7Blnx%7D%7Bx%7D%5D)
Using the quotient rule:


For maximum, f'(x) = 0;


(b) <em>Deduce:
</em>

<em>
Soln:</em> Since x = e is the greatest value, then f(e) ≥ f(x) > f(0)


, since ln(e) is simply equal to 1
Now, since x > 0, then we don't have to worry about flipping the signs when multiplying by x.



Taking the exponential to both sides will cancel with the natural logarithmic function in the right hand side to produce:


, as required.
SA= bh+2ls+lw
SA= 26*10 +40*26(2)+40*10
SA=260+1040(2)+400
SA=260+2080+400
SA=2740
First, it would help to put 46 and 2/3 into an improper fraction: 140/3.
Then, since this is a percent, we put that improper fraction over 100: (140/3)/100 = 140/300.
Finally, we multiply this answer by 28 since "of" means multiply:
(140/300) * 28 = 196/15 = 13 1/15
Add 0.1 to 0.0(54) to get 0.1(54).
You would plot them by month, 170-110= 60 dollar increase. 60 divided by 12 ( for each month) leaves a 5 dollar increase each month. Your coordinates would be 0,110 1,115 2,120 3,125
x would be month
y would be money