
(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 answer to your question is: (∞ , 3]
Step-by-step explanation:
Remember that to express an inequality, are used ( ) and [ ].
( ) are used when the point is not consider in the interval.
[ ] are used when the point is consider or is part of the interval.
Also, an empty point indicates that the number is not consider in the interval.
and, a filled point indicates that the number is consider in the interval.
For your question, the interval will be:
(∞ , 3]
Step-by-step explanation:
the answer in the picture that i sent
Answer:
y=27
Step-by-step explanation: