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 7b

Let f(x)=x24x2f\(\left\)(x\(\right\))=\(\frac{x^2-4}{x-2}\). <IMAGE>
Make a conjecture about the value of limx2x24x2{\(\displaystyle\]\lim\)_{x\(\to\)2}\(\frac{x^2-4}{x-2}\)}.

검증된 단계별 안내
1
First, recognize that the expression \( \frac{x^2 - 4}{x - 2} \) is undefined at \( x = 2 \) because it results in division by zero. Therefore, we need to simplify the expression to evaluate the limit.
Notice that the numerator \( x^2 - 4 \) can be factored as a difference of squares: \( x^2 - 4 = (x - 2)(x + 2) \).
Substitute the factored form into the original expression: \( \frac{(x - 2)(x + 2)}{x - 2} \).
Cancel the common factor \( (x - 2) \) in the numerator and the denominator, which simplifies the expression to \( x + 2 \), provided \( x \neq 2 \).
Now, evaluate the limit of the simplified expression as \( x \to 2 \): \( \lim_{x \to 2} (x + 2) \). This can be directly computed by substituting \( x = 2 \) into the expression, leading to the conjecture about the limit.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m
도움이 되었나요?

주요 개념

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

Limits

A limit is a fundamental concept in calculus that describes the behavior of a function as its input approaches a certain value. It helps in understanding the function's behavior near points where it may not be explicitly defined, such as points of discontinuity. In this question, we are interested in the limit of the function as x approaches 2, which is crucial for evaluating the function's value at that point.
추천 영상:
05:50
One-Sided Limits

Factoring Polynomials

Factoring polynomials involves rewriting a polynomial as a product of simpler polynomials or expressions. In the given function, f(x) = (x^2 - 4)/(x - 2), the numerator can be factored as (x - 2)(x + 2). This simplification is essential for evaluating the limit, as it allows us to cancel out the common factor in the numerator and denominator, making the limit easier to compute.
추천 영상:
07:00
Taylor Polynomials

Continuity

Continuity refers to a function being unbroken or having no gaps at a certain point. A function is continuous at a point if the limit as x approaches that point equals the function's value at that point. In this case, understanding continuity is important because it helps us determine whether the limit we compute will yield a valid function value at x = 2, which is initially undefined in the original function.
추천 영상:
05:34
Intro to Continuity