How to find lim(ln(2x)/(2+x)) x-> infinity?

2 Answers
Sep 3, 2017

The limit equals 0

Explanation:

Since we are of the form oo/oo, we can use L'Hospitals rule.

L = lim_(x->oo) (2/(2x))/(1)

L = lim_(x->oo) 1/x

This is now a recognizable and commonly seen limit.

L = 0

Hopefully this helps!

Sep 4, 2017

lim_(xrarroo)ln(2x)/(2+x)=0

Explanation:

Logarithmic functions grow slower than polynomial functions. Polynomial functions grow slower than exponential functions.

Since ln(2x) is logarithmic and 2+x is a polynomial (it only has a degree of 1, but it's still a polynomial), the polynomial in the denominator will grow faster than the logarithmic function in the numerator.

Thus, the denominator will outpace the numerator and as x goes to infinity, the limit approaches 0.

Note what would happen if the fraction were inverted:

lim_(xrarroo)ln(2x)/(2+x)=0

lim_(xrarroo)(2+x)/ln(2x)=oo