# Simple optimization problem 2

Approaching this question, I first calculated the TOTAL cost of the trip (that is, $D(v) + F(v))$. This gave me $\dfrac{1}{v} (5v^{\frac 5 2} + 2059V + 150 000)$.

Am I right in saying I now have to calculate this cost in cents per km? And would I do this by dividing the cost (in cents per trip) by $v$?

• What you have computed (and I think it should be $\frac{2\nu^{\frac{5}{2}} + 2059\nu + 150000}{\nu}$ ) is the cost per trip. Since what you are asked is most economical speed for the trip and the cost for the trip, you just need to minimize the expression that you have computed. – Malcolm Mar 18 '18 at 0:31
• @Malcolm ah! Thank you! – Lara Jane Mar 18 '18 at 1:17