Skip to main content
Ch. 11 - Parametric Equations and Polar Coordinates
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Non è quello che usi tu?Cambia libro di testo
Capitolo 11, Problema 11.PE.12a

Finding Parametric Equations and Tangent Lines


Find parametric equations for the given curve.


Line through (1,-2) with slope 3

Guida verificata passo dopo passo
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.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
1m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

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.
Video consigliato:
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.
Video consigliato:
Percorso guidato
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.
Video consigliato:
Percorso guidato
05:13
Slopes of Tangent Lines
Pratica correlata
Domanda del libro di testo

Finding Parametric Equations and Tangent Lines


Find parametric equations for the given curve.


9x² + 4y² = 36

18
views
Domanda del libro di testo

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
Domanda del libro di testo

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
Domanda del libro di testo

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
Domanda del libro di testo

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
Domanda del libro di testo

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