/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 13 Find the line integrals along th... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the line integrals along the given path \(C.\) \(\int_{C}(x-y) d x,\) where \(C: x=t, y=2 t+1,\) for \(0 \leq t \leq 3\)

Short Answer

Expert verified
The line integral along the path is \(-\frac{15}{2}\).

Step by step solution

01

Parameterize the Path

The path is given by the equations \(x = t\) and \(y = 2t + 1\) as a function of \(t\). This path parameterization describes how \(x\) and \(y\) change as \(t\) varies from 0 to 3.
02

Determine the Differential Components

For the integral \(\int_C (x-y) \, dx\), the differential component \(dx\) is equal to \(dt\) since \(x = t\). Therefore, the integral with \(x\) and \(y\) becomes \(\int_0^3 (t - (2t + 1)) \, dt\).
03

Simplify the Integrand

Substitute \(x = t\) and \(y = 2t + 1\) into the integrand: \(x - y = t - (2t + 1) = -t - 1\).Thus, the integral becomes \(\int_0^3 (-t - 1) \, dt\).
04

Calculate the Integral

Evaluate the integral \(\int_0^3 (-t - 1) \, dt\):First, integrate \[\int(-t) \, dt = -\frac{t^2}{2},\] and \[\int(-1) \, dt = -t.\]Thus, we find:\[\left[-\frac{t^2}{2} - t\right]_0^3.\]
05

Evaluate the Definite Integral

Apply the limits of integration from 0 to 3:\[\left[-\frac{3^2}{2} - 3\right] - \left[-\frac{0^2}{2} - 0\right] = \left[-\frac{9}{2} - 3\right] - [0] = -\frac{9}{2} - 3 = -\frac{15}{2}.\]

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Path Parameterization
In line integrals, parameterizing the path is an essential step. It involves expressing the variables of the path, like \(x\) and \(y\), in terms of a single parameter, often \(t\).
This parameterization transforms the path into a more manageable form. For example, in our exercise, the path is given by:\(x = t\) and \(y = 2t + 1\).
This means as \(t\) varies from 0 to 3, \(x\) and \(y\) will adapt according to these expressions. This simple yet powerful technique breaks down complex paths into linear equations based on \(t\).
  • Choose a parameter, often \(t\), to simplify integration.
  • Express all path variables in terms of \(t\).
  • Define the limits of \(t\) according to the path's boundaries.
Integral Evaluation
Evaluating an integral involves several crucial steps to ensure it's solved correctly. First, substitute the parameterized variables into the integral expression. For our example, the integral \(\int_{C}(x-y) \, dx\) becomes \(\int_{0}^{3}(t-(2t+1)) \, dt\).
This step is about replacing the path variables with their parameter \(t\), aligning with how the path is parameterized.
  • Substitute the parameterized equations into the integral.
  • Simplify the integrand as needed after substitution.
  • Ensure the integral's differential component corresponds to the chosen parameter.
Differential Components
Differential components in line integrals indicate how to integrate with respect to a chosen parameter. In this exercise, \(dx\) reflects the rate of change of \(x\) with respect to \(t\), which simplifies to \(dt\) when \(x = t\).
The differential component effectively translates the problem from a multi-variable point of view to a single-variable context, making integration feasible.
  • The differential \(dx\) aligns with the parameterization \(x = t\).
  • In this context, it simplifies the task to integrating terms involving \(t\) with respect to \(t\).
  • This step ensures consistency and correctness in the integral evaluation.
Definite Integral Calculation
Calculating the definite integral requires evaluating the expression between specified limits. In the given exercise, the limits for \(t\) are from 0 to 3. By integrating the expression \((-t - 1)\) with respect to \(t\), we first determine the antiderivative, resulting in \(-\frac{t^2}{2} - t\).
Then, apply the limits:
- Evaluate at the upper limit (\(t = 3\)) and the lower limit (\(t = 0\)).
- Calculate \([-\frac{9}{2} - 3] - [0]\) to finalize the definite integral evaluation.
- This process results in \(-\frac{15}{2}\), which is the value of the line integral over the path, reflecting the overall accumulation dictated by the path's function.
  • Find the antiderivative of the integrand.
  • Apply the upper and lower limits to the antiderivative.
  • Subtract these values to find the integral's result.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Find the area of the cap cut from the sphere \(x^{2}+y^{2}+z^{2}=2\) by the cone \(z=\sqrt{x^{2}+y^{2}}\)

Find the work done by \(\mathbf{F}\) in moving a particle once counterclockwise around the given curve. \(\mathbf{F}=2 x y^{3} \mathbf{i}+4 x^{2} y^{2} \mathbf{j}\) C: The boundary of the "triangular" region in the first quadrant enclosed by the \(x\) -axis, the line \(x=1,\) and the curve \(y=x^{3}\)

The parametrization a. and \(x=a \cos \theta, \quad y=b \sin \theta, \quad 0 \leq \theta \leq 2 \pi\) gives the ellipse \(\left(x^{2} / a^{2}\right)+\left(y^{2} / b^{2}\right)=1 .\) Using the angles \(\theta\) and \(\phi\) in spherical coordinates, show that $$\mathbf{r}(\theta, \phi)=(a \cos \theta \cos \phi) \mathbf{i}+(b \sin \theta \cos \phi) \mathbf{j}+(c \sin \phi) \mathbf{k}$$ is a parametrization of the ellipsoid \(\left(x^{2} / a^{2}\right)+\left(y^{2} / b^{2}\right)+\) \(\left(z^{2} / c^{2}\right)=1\) b. Write an integral for the surface area of the ellipsoid, but do not evaluate the integral.

\(\mathbf{F}\) is the velocity field of a fluid flowing through a region in space. Find the flow along the given curve in the direction of increasing \(t.\) $$\begin{aligned} &\mathbf{F}=(x-z) \mathbf{i}+x \mathbf{k}\\\ &\mathbf{r}(t)=(\cos t) \mathbf{i}+(\sin t) \mathbf{k}, \quad 0 \leq t \leq \pi \end{aligned}$$

Use the surface integral in Stokes' Theorem to calculate the circulation of the field \(\mathbf{F}\) around the curve \(C\) in the indicated direction. \(\mathbf{F}=y \mathbf{i}+x z \mathbf{j}+x^{2} \mathbf{k}\),\(C:\) The boundary of the triangle cut from the plane \(x+y+z=1\) by the first octant, counterclockwise when viewed from above.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.