Skip to main content
Ch. 3 - Derivatives
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 3.95b

Right circular cylinder The total surface area S of a right circular cylinder is related to the base radius r and height h by the equation S = 2πr² + 2πrh.


b. How is dS/dt related to dh/dt if r is constant?

검증된 단계별 안내
1
Start by understanding the given formula for the total surface area of a right circular cylinder: \( S = 2\pi r^2 + 2\pi rh \). Here, \( r \) is the radius of the base, and \( h \) is the height of the cylinder.
Since \( r \) is constant, the term \( 2\pi r^2 \) is also constant, and its derivative with respect to time \( t \) is zero. Therefore, focus on differentiating the term \( 2\pi rh \) with respect to \( t \).
Apply the product rule to differentiate \( 2\pi rh \) with respect to \( t \). The product rule states that \( \frac{d}{dt}(uv) = u \frac{dv}{dt} + v \frac{du}{dt} \). Here, \( u = 2\pi r \) (a constant) and \( v = h \).
Differentiate \( 2\pi rh \) using the product rule: \( \frac{d}{dt}(2\pi rh) = 2\pi r \frac{dh}{dt} \). Since \( r \) is constant, \( \frac{dr}{dt} = 0 \), and the derivative simplifies to \( 2\pi r \frac{dh}{dt} \).
Thus, the rate of change of the surface area \( \frac{dS}{dt} \) with respect to time is directly proportional to the rate of change of the height \( \frac{dh}{dt} \), given by the expression \( \frac{dS}{dt} = 2\pi r \frac{dh}{dt} \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
4m
도움이 되었나요?

주요 개념

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

Related Rates

Related rates are a concept in calculus that deals with the relationship between different rates of change. When two or more variables are related by an equation, the rate of change of one variable can be expressed in terms of the rate of change of another. In this context, we are interested in how the surface area of the cylinder changes with respect to time as the height changes, while keeping the radius constant.
추천 영상:
가이드 코스
04:16
Intro To Related Rates

Differentiation

Differentiation is a fundamental concept in calculus that involves finding the derivative of a function. The derivative represents the rate of change of a function with respect to a variable. In this problem, we will differentiate the surface area equation with respect to time to find the relationship between the rates of change of surface area and height.
추천 영상:
가이드 코스
05:53
Finding Differentials

Implicit Differentiation

Implicit differentiation is a technique used to differentiate equations that define one variable in terms of another without explicitly solving for one variable. In this case, we will apply implicit differentiation to the surface area equation to relate the change in surface area to the change in height, while treating the radius as a constant. This allows us to find the desired relationship between dS/dt and dh/dt.
추천 영상:
가이드 코스
05:14
Finding The Implicit Derivative