What is the limit of sqrt(x^3-2x^2+1)/[x-1] as x goes to infinity?

1 Answer
Oct 17, 2015

lim_(xrarroo)sqrt(x^3-2x^2+1)/(x-1) = oo

Explanation:

sqrt(x^3-2x^2+1) = sqrt(x^2(x-2+1/x^2))

= sqrt(x^2)sqrt(x-2+1/x^2)

= absx sqrt(x-2+1/x^2)

So

lim_(xrarroo)sqrt(x^3-2x^2+1)/(x-1) = lim_(xrarroo)(absx sqrt(x-2+1/x^2))/(x(1-1/x))

= lim_(xrarroo)(sqrt(x-2+1/x^2))/(1-1/x)

= oo