Find answers to your most challenging questions with the help of IDNLearn.com's experts. Our experts provide timely, comprehensive responses to ensure you have the information you need.

Evaluate the following limit:

[tex]\[ \lim _{x \rightarrow 0} \frac{x}{\sin ^{-1} x} \][/tex]


Sagot :

To find the limit of [tex]\(\frac{x}{\sin^{-1} x}\)[/tex] as [tex]\(x\)[/tex] approaches 0, we can follow these steps:

1. Understand the Expression:
We need to evaluate [tex]\(\lim_{x \to 0} \frac{x}{\sin^{-1} x}\)[/tex].

2. Behavior at the Limit Point:
As [tex]\(x\)[/tex] approaches 0, both [tex]\(x\)[/tex] and [tex]\(\sin^{-1} x\)[/tex] approach 0. This suggests we might use L'Hôpital's Rule, which is applicable for limits of the form [tex]\(\frac{0}{0}\)[/tex].

3. Apply L'Hôpital's Rule:
L'Hôpital's Rule states that if [tex]\(\lim_{x \to c} \frac{f(x)}{g(x)} = \frac{0}{0}\)[/tex] or [tex]\(\frac{\pm \infty}{\pm \infty}\)[/tex], then
[tex]\[ \lim_{x \to c} \frac{f(x)}{g(x)} = \lim_{x \to c} \frac{f'(x)}{g'(x)}, \][/tex]
provided the limit on the right side exists.

Here, let [tex]\(f(x) = x\)[/tex] and [tex]\(g(x) = \sin^{-1} x\)[/tex]. Both functions are differentiable around [tex]\(x = 0\)[/tex].

4. Differentiate the Numerator and Denominator:
- The derivative of [tex]\(f(x) = x\)[/tex] is [tex]\(f'(x) = 1\)[/tex].
- The derivative of [tex]\(g(x) = \sin^{-1} x\)[/tex] is [tex]\(g'(x) = \frac{1}{\sqrt{1 - x^2}}\)[/tex].

5. Apply L'Hôpital's Rule:
Therefore,
[tex]\[ \lim_{x \to 0} \frac{x}{\sin^{-1} x} = \lim_{x \to 0} \frac{1}{\frac{1}{\sqrt{1 - x^2}}}. \][/tex]

6. Simplify the Expression:
Simplify the fraction:
[tex]\[ \lim_{x \to 0} \frac{1}{\frac{1}{\sqrt{1 - x^2}}} = \lim_{x \to 0} \sqrt{1 - x^2}. \][/tex]

7. Evaluate the Limit:
As [tex]\(x\)[/tex] approaches 0, the expression [tex]\(\sqrt{1 - x^2}\)[/tex] approaches [tex]\(\sqrt{1 - 0} = 1\)[/tex].

Therefore,
[tex]\[ \lim_{x \rightarrow 0} \frac{x}{\sin^{-1} x} = 1. \][/tex]

So, the limit is [tex]\(\boxed{1}\)[/tex].