Answer:
77
Step-by-step explanation:
Plug in:
F(4) = (4)3 + 2(4)2 + 1
F(4) = 12 + (8)^2 + 1
F(4) = 12 + 64 + 1
F(4) = 77
(assuming 2x2 = 2x squared)
-625
use long multiplication to evaluate .

(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.
Assume the radius is R.
2*pi*R = 28 -> R = 14/pi
So the area will be pi*R^2 = 196/pi