Skip to main content
Ch. 2 - Limits
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 77a

Analyze lim x→∞ f(x) and lim x→−∞ f(x), and then identify any horizontal asymptotes.


f(x)=√x^2+2x+6−3 / x−1

검증된 단계별 안내
1
Step 1: Identify the dominant terms in the numerator and the denominator as x approaches infinity. For the function \( f(x) = \frac{\sqrt{x^2 + 2x + 6} - 3}{x - 1} \), the dominant term in the numerator is \( \sqrt{x^2} = x \) and in the denominator is \( x \).
Step 2: Simplify the expression by dividing both the numerator and the denominator by the dominant term \( x \). This gives \( \frac{\sqrt{x^2 + 2x + 6}/x - 3/x}{x/x - 1/x} \).
Step 3: Simplify further by recognizing that \( \sqrt{x^2 + 2x + 6}/x = \sqrt{1 + 2/x + 6/x^2} \). As \( x \to \infty \), \( 2/x \to 0 \) and \( 6/x^2 \to 0 \), so \( \sqrt{1 + 2/x + 6/x^2} \to 1 \).
Step 4: Evaluate the limit as \( x \to \infty \). The expression simplifies to \( \frac{1 - 0}{1 - 0} = 1 \). Therefore, \( \lim_{x \to \infty} f(x) = 1 \).
Step 5: Evaluate the limit as \( x \to -\infty \). The dominant term in the numerator becomes \( -x \) because \( \sqrt{x^2} = |x| \) and \( x \) is negative. Simplifying the expression similarly, we find \( \lim_{x \to -\infty} f(x) = -1 \). Thus, the horizontal asymptotes are \( y = 1 \) and \( y = -1 \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
5m
도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Limits at Infinity

Limits at infinity involve evaluating the behavior of a function as the input approaches positive or negative infinity. This analysis helps determine the end behavior of the function, which is crucial for identifying horizontal asymptotes. For rational functions, this often involves comparing the degrees of the numerator and denominator.
추천 영상:
05:50
One-Sided Limits

Horizontal Asymptotes

Horizontal asymptotes are lines that a graph approaches as the input values become very large or very small. They indicate the value that the function approaches at infinity. To find horizontal asymptotes, one typically evaluates the limits of the function as x approaches positive and negative infinity.
추천 영상:
5:46
Graphs of Exponential Functions

Rational Functions

Rational functions are expressions formed by the ratio of two polynomials. The behavior of these functions at infinity is influenced by the degrees of the polynomials in the numerator and denominator. Understanding how to simplify and analyze these functions is essential for determining limits and asymptotic behavior.
추천 영상:
6:04
Intro to Rational Functions