Calculus
posted by Johny .
what happens when the limit goes to infinity
4x6sqrt(x)

since x grows faster than sqrt(x)
f(x) > oo as x >oo
In fact, x grows so much faster than sqrt(x),f(x) > 4x
When x is 10000, 4x/f(x) = 1.015
when x is 1000000, 4x/f(x) = 1.002