Evaluate the limit x → + ∞ lim 3 x 3 + 1 x 2 − 3 .
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
You may transform the function into 6 ( x 3 + 1 ) 2 ( x 2 − 3 ) 3 = 6 x 6 + 2 x 3 + 1 x 6 − 9 x 4 + 2 7 x 2 − 2 7 Evaluating limit will give 6 1 = 1
Thanks for your solution! However, there's an even easier way, i think.
Log in to reply
L'hopital is likely to be the last method if I encounter to strange function, but as this is a polynomial, I decided to take one instead.
Log in to reply
You don't need L'Hopital's here, you can either apply end behavior by just looking at it, or use the standard method I just posted.
Problem Loading...
Note Loading...
Set Loading...
The standard method is to divide each term by the highest power term in the denominator. In this case, it's x. We don't have to bother with absolute values because x is approaching positive infinity in this case. x → ∞ lim x 3 x 3 + 1 x x 2 − 3 = x → ∞ lim 3 x 3 3 x 3 + 1 x 2 x 2 − 3 = x → ∞ lim 3 x 3 x 3 + x 3 1 x 2 x 2 − x 2 3 Cancel, and apply the rule that x → ∞ lim x n k = 0 , where k is a constant. You're left with x → ∞ lim 1 1 which is simply 1