
(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.
Answer:
the last one 
Step-by-step explanation:
Answer:
0.06
Step-by-step explanation:
Move variable to the left. -w= -10+ 4W
-w-4W =-10
Collect like terms
-5w=-10 divide both sides by 5
Answer:
Amanda= 14
Boris = 88
Jose= 22
Step-by-step explanation:
Amanda= jose-8
Boris = 4×jose
Jose= Jose
total all = 124
(jose-8)+(jose×4)+(jose)= 124
so we substitute jose with X .
(X-8)+(4X)+(X)=124
6X-8= 124.
6X=124+8
X=132/6
X= 22.
so that total jose is 22, minus 8 we get Amanda, times 4 we get Boris.