Skip to main content
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.12a

Finding Parametric Equations and Tangent Lines


Find parametric equations for the given curve.


Line through (1,-2) with slope 3

검증된 단계별 안내
1
Recall that a parametric equation for a line can be expressed as \(x = x_0 + at\) and \(y = y_0 + bt\), where \((x_0, y_0)\) is a point on the line and \((a, b)\) is a direction vector parallel to the line.
Identify the given point on the line as \((1, -2)\), so \(x_0 = 1\) and \(y_0 = -2\).
Use the slope of the line, which is 3, to find the direction vector. Since slope \(m = \frac{b}{a} = 3\), you can choose \(a = 1\) and \(b = 3\) for simplicity.
Write the parametric equations using the point and direction vector: \(x = 1 + 1 \cdot t\) and \(y = -2 + 3 \cdot t\).
These parametric equations describe the line passing through \((1, -2)\) with slope 3, where \(t\) is the parameter.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m
도움이 되었나요?

주요 개념

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

Parametric Equations

Parametric equations express a curve by defining both x and y coordinates as functions of a third variable, usually t. This allows representation of curves that are difficult to describe with a single function y = f(x). For example, a line can be represented as x = x0 + at and y = y0 + bt, where (x0, y0) is a point on the line and (a, b) relates to the direction.
추천 영상:
가이드 코스
08:02
Parameterizing Equations

Equation of a Line Using Point-Slope Form

The point-slope form of a line is y - y1 = m(x - x1), where (x1, y1) is a point on the line and m is the slope. This form is useful for quickly writing the equation of a line when a point and slope are known. It can be rearranged or converted into parametric form for further analysis.
추천 영상:
05:13
Slopes of Tangent Lines

Tangent Lines and Their Slopes

A tangent line to a curve at a point touches the curve without crossing it and has the same slope as the curve at that point. For parametric curves, the slope of the tangent line is found by dy/dx = (dy/dt) / (dx/dt). Understanding tangent lines helps in analyzing the behavior and direction of curves.
추천 영상:
05:13
Slopes of Tangent Lines
관련 실천
교과서 질문

Finding Parametric Equations and Tangent Lines


Find parametric equations for the given curve.


9x² + 4y² = 36

18
views
교과서 질문

Identifying Conic Sections


Complete the squares to identify the conic sections in Exercises 69-76. Find their foci, vertices, centers, and asymptotes (as appropriate). If the curve is a parabola, find its directrix as well.


x² + y² + 4x + 2y = 1

34
views
교과서 질문

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

38
views
교과서 질문

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 = 4 cos t, y = 9 sin t, 0 ≤ t ≤ 2π

29
views
교과서 질문

Graphing Conic Sections


Find the eccentricities of the ellipses and hyperbolas in Exercises 59–62. Sketch each conic section. Include the foci, vertices, and asymptotes (as appropriate) in your sketch.


5y² − 4x² = 20

31
views
교과서 질문

Polar to Cartesian Equations


Sketch the lines in Exercises 23-28. Also, find a Cartesian equation for each line.


r cos (θ − 3π/4) = (√2)/2

25
views