a minimum with constants

[raven720]

E(v) = aLv^3/v-u

Find the minimum for v
Where u < v
a is a constant
L is some distance
u some resistance force

I know how to find mins and maxs but i have seem to have trouble when constants are involved, specially when trying to take the derivitive

 

[BigGlenntheHeavy]

\(\displaystyle E(v) \ = \ \frac{aLv^{3}}{v-u}\)

\(\displaystyle \frac{dE}{dv} \ = \ \frac{(v-u)(3aLv^{2})-(aLv^{3})(1)}{(v-u)^{2}}\)

\(\displaystyle You \ should \ be \ able \ to \ finish \ up \ from \ here.\)