Вопрос
4.26. lim _(xarrow 5)((1)/(x-5)-(5)/(x^2)-x-20)
Решения
4.5
(276 Голоса)
Евстигней
Экспертная проверка
мастер · Репетитор 5 лет
Ответ
To find the limit of the given expression as
approaches 5, we need to simplify the expression first.The expression is:
First, let's factor the denominator in the second term:
So the expression becomes:
Next, we combine the fractions over a common denominator:
Simplify the numerator:
So the expression now is:
As
approaches 5, the denominator \((x-5)\) approaches 0, which means the expression is in an indeterminate form
. To resolve this, we can use L'Hôpital's Rule, which states that if the limit of \(\frac{f(x)}{g(x)}\) as
approaches
is in the form
or
, then:
Let \( f(x) = x-1 \) and \( g(x) = (x-5)(x+4) \).Now, we find the derivatives:
Now apply L'Hôpital's Rule:
Finally, substitute
:
So, the limit is: