Skip to main content
Ch.12 - Parametric and Polar Curves
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243당신이 사용하는 게 아니라요?교과서 변경
12장, 문제 12.1.73

73–76. Tangent lines Find an equation of the line tangent to the curve at the point corresponding to the given value of t.


x=t ²−1, y=t ³ +t; t=2

검증된 단계별 안내
1
Identify the parametric equations given: \(x = t^{2} - 1\) and \(y = t^{3} + t\), and the value of the parameter \(t = 2\) at which we want the tangent line.
Find the derivatives of \(x\) and \(y\) with respect to \(t\): compute \(\frac{dx}{dt}\) and \(\frac{dy}{dt}\). For \(x = t^{2} - 1\), \(\frac{dx}{dt} = 2t\). For \(y = t^{3} + t\), \(\frac{dy}{dt} = 3t^{2} + 1\).
Calculate the slope of the tangent line \(\frac{dy}{dx}\) at \(t=2\) using the chain rule for parametric equations: \(\frac{dy}{dx} = \frac{\frac{dy}{dt}}{\frac{dx}{dt}}\) evaluated at \(t=2\).
Find the coordinates of the point on the curve at \(t=2\) by substituting \(t=2\) into the parametric equations: \(x(2)\) and \(y(2)\).
Use the point-slope form of the line equation with the point \((x(2), y(2))\) and slope \(\frac{dy}{dx}\) to write the equation of the tangent line: \(y - y(2) = m (x - x(2))\), where \(m\) is the slope found in the previous step.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m

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 denoted as t. Here, x and y are given in terms of t, allowing us to analyze the curve's behavior by varying t.
추천 영상:
08:02
Parameterizing Equations

Derivative of Parametric Curves

To find the slope of the tangent line to a parametric curve, we compute dy/dx as (dy/dt) divided by (dx/dt). This ratio gives the instantaneous rate of change of y with respect to x at a specific parameter value.
추천 영상:
가이드 코스
06:49
Differentiation of Parametric Curves

Equation of a Tangent Line

Once the slope of the tangent line and the point of tangency are known, the tangent line's equation can be written using the point-slope form: y - y₀ = m(x - x₀), where m is the slope and (x₀, y₀) is the point on the curve.
추천 영상:
가이드 코스
05:14
Equations of Tangent Lines