True or false
Let P ( x ) = 1 + x + 2 ! x 2 + 3 ! x 3 + ⋯ + n ! x n , where n is a very large positive integer
Then x → ∞ lim P ( x ) e x = 1
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.
The problem states that n is a large positive integer, however infinity is not a number and so the limit would only equal 1 if P ( x ) was an infinite series instead of a partial sum terminating at some large positive integer n . The limit in question is undefined.
Problem Loading...
Note Loading...
Set Loading...
x → ∞ lim P ( x ) e x = x → ∞ lim r = 0 ∑ n r ! x r r = 0 ∑ ∞ r ! x r = x → ∞ lim r = 0 ∑ n r ! x r r = 0 ∑ n r ! x r + r = n + 1 ∑ ∞ r ! x r = x → ∞ lim ⎣ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎢ ⎡ 1 + → ∞ as x → ∞ r = 0 ∑ n r ! x r r = n + 1 ∑ ∞ r ! x r ⎦ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎥ ⎤
Thus limit diverges and statement is false .