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use lhôpitals rule to evaluate $limlimits_{x\to+infty}\frac{3x^{2}-7x}{…

Question

use lhôpitals rule to evaluate $limlimits_{x\to+infty}\frac{3x^{2}-7x}{7x^{2}+5}$. then determine the limit using limit laws and commonly known lim
use lhôpitals rule to rewrite the given limit so that it is not an indeterminate form.
$limlimits_{x\to+infty}\frac{3x^{2}-7x}{7x^{2}+5}=limlimits_{x\to+infty}(square)$

Explanation:

Step1: Apply L'Hopital's Rule

L'Hopital's Rule states that if \(\lim_{x
ightarrow a}\frac{f(x)}{g(x)}\) is in the indeterminate form \(\frac{\infty}{\infty}\) or \(\frac{0}{0}\), then \(\lim_{x
ightarrow a}\frac{f(x)}{g(x)}=\lim_{x
ightarrow a}\frac{f^{\prime}(x)}{g^{\prime}(x)}\).
For \(f(x) = 3x^{2}-7x\), \(f^{\prime}(x)=6x - 7\).
For \(g(x)=7x^{2}+5\), \(g^{\prime}(x)=14x\).
So, \(\lim_{x
ightarrow\infty}\frac{3x^{2}-7x}{7x^{2}+5}=\lim_{x
ightarrow\infty}\frac{6x - 7}{14x}\).

Step2: Check the form and apply L'Hopital's Rule again (if needed)

The limit \(\lim_{x
ightarrow\infty}\frac{6x - 7}{14x}\) is still in the \(\frac{\infty}{\infty}\) form.
Differentiate \(f_1(x)=6x - 7\) (so \(f_1^{\prime}(x)=6\)) and \(g_1(x)=14x\) (so \(g_1^{\prime}(x)=14\)).
Then \(\lim_{x
ightarrow\infty}\frac{6x - 7}{14x}=\lim_{x
ightarrow\infty}\frac{6}{14}\).

Answer:

\(\frac{3}{7}\)