Skip to main content
Ch. 2 - Limits and Continuity
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 13

Finding Limits
In Exercises 9–24, find the limit or explain why it does not exist.




lim h →0 ((x + h)² ― x²)/h

검증된 단계별 안내
1
Recognize that the given expression is a difference quotient, which is often used to find the derivative of a function at a point. Here, the function is f(x) = x².
Substitute the expression (x + h)² for f(x + h) in the difference quotient: ((x + h)² - x²)/h.
Expand the expression (x + h)² using the binomial theorem: (x + h)² = x² + 2xh + h².
Substitute the expanded form back into the difference quotient: ((x² + 2xh + h²) - x²)/h.
Simplify the expression by canceling out x² and then dividing each term by h: (2xh + h²)/h = 2x + h. Now, take the limit as h approaches 0, which results in the derivative of x² at x.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m
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 how functions behave near specific points, which is crucial for defining derivatives and integrals. In this case, we are interested in the limit as h approaches 0, which is essential for evaluating the expression given.
추천 영상:
05:50
One-Sided Limits

Difference Quotient

The difference quotient is a formula that represents the average rate of change of a function over an interval. It is expressed as (f(x + h) - f(x)) / h, and is used to derive the derivative of a function. In the given limit problem, the expression ((x + h)² - x²)/h is a difference quotient that simplifies to find the derivative of the function f(x) = x².
추천 영상:
06:43
The Quotient Rule

Derivative

The derivative of a function at a point measures the instantaneous rate of change of the function at that point. It is defined as the limit of the difference quotient as the interval approaches zero. In this exercise, finding the limit will ultimately yield the derivative of the function f(x) = x², which is a key application of limits in calculus.
추천 영상:
05:44
Derivatives