Multiple Choice:
A point moves on the x-axis in such a way that its velocity at time t (t>0) is given by v=lnt/t. At which value of t does v attain its maximum?
(A) 1
(B) e^(1/2)
(C) e
(D) e^(3/2)
(E) There is no maximum value for v.

Respuesta :

dv/dt = [tex] \frac{t* \frac{1}{t}-1*lnt }{ t^{2} } = \\ = \frac{1-+lnt}{t^{2} } [/tex]
Velocity attains its maximum at dv/dt = 0, or:
1 - ln t = 0
ln t = 1
[tex] log_{e}t= 1 [/tex]
t = e
Answer: C)