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Ch. 11 - Parametric Equations and Polar Coordinates
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
11장, 문제 11.PE.2

Identifying Parametric Equations in the Plane


Exercises 1–6 give parametric equations and parameter intervals for the motion of a particle in the xy-plane. Identify the particle’s path by finding a Cartesian equation for it. Graph the Cartesian equation and indicate the direction of motion and the portion traced by the particle.


x = √t, y = 1 − √t, t ≥ 0

검증된 단계별 안내
1
Start with the given parametric equations: \(x = \sqrt{t}\) and \(y = 1 - \sqrt{t}\), where \(t \geq 0\).
Express \(\sqrt{t}\) in terms of \(x\) from the first equation: \(\sqrt{t} = x\).
Substitute \(\sqrt{t} = x\) into the second equation to eliminate the parameter \(t\): \(y = 1 - x\).
Recognize that the Cartesian equation of the path is \(y = 1 - x\), which is a straight line.
Determine the portion of the line traced by the particle by considering the domain of \(t\): since \(t \geq 0\), and \(x = \sqrt{t}\), then \(x \geq 0\). So the particle moves along the line \(y = 1 - x\) for \(x \geq 0\), starting at the point \((0,1)\) and moving in the direction of increasing \(x\).

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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주요 개념

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

Parametric Equations

Parametric equations express the coordinates of points on a curve as functions of a parameter, often time (t). Instead of y as a function of x, both x and y depend on t, allowing the description of more complex motions and paths in the plane.
추천 영상:
가이드 코스
08:02
Parameterizing Equations

Eliminating the Parameter

To find the Cartesian equation from parametric equations, solve one equation for the parameter and substitute into the other. This process removes the parameter, yielding a direct relationship between x and y that describes the particle’s path.
추천 영상:
가이드 코스
05:59
Eliminating the Parameter

Direction and Domain of the Parameter

The parameter interval defines the portion of the curve traced and the direction of motion. Understanding the range of t and how x and y change with t helps determine which part of the Cartesian curve corresponds to the particle’s path and its movement direction.
추천 영상:
가이드 코스
05:59
Eliminating the Parameter