Determine the global extrema for f(x) = logX /x over [1,10]

y = lnx/x

y' = (1-lnx)/x^2
y'=0 when x=e
y(1) = 0
y(e) = 1/e = 0.36
y(10) = ln10/10 = 0.23
so max at (1,1/e)
min at (0,0)