#Difficult limit problem calculus
19 messages · Page 1 of 1 (latest)
take the natural log, and see what you get
$e^{\lim_{t\to\infty}t\ln\left(1-\frac{3}{t}\right)}$
k
now, find the limit of the exponent
Can you just take the log of a limit and it remains the same?
Confused how you did that
Oh wait, it is e raised to the limit
Thats really weird, let me see if I can figure that out though
e^(ln(x))=x
Thanks for the help @runic pasture !
@terse dove has given 1 rep to @runic pasture
This uses the composition law for limits
if lim_x->c g(x)=G, then lim_x->c f(g(x))= lim_x->G f(x) = L
So if f is continuous at L, L = f(G). In this specific example f would be e^t and g would be tln(1+1/t)
This is a very powerful result with limits and is worth spending time on understanding
@terse dove
As for how to evaluate the new limit, tln(1+1/t) is the same as ln(1+1/t)/(1/t)
Evaluating this at infinity gives you 0/0 so lhoptials rule is applicable