Solving Line Integral on Curve C

Click For Summary
SUMMARY

The discussion focuses on evaluating the line integral \(\int(y^2-x^2)ds\) along the curve defined by the parametric equations \(x = 3t(1+t)\) and \(y = t^3\) for \(0 \leq t \leq 2\). The differential arc length \(ds\) is calculated as \(ds = 3\sqrt{t^4 + 4t^2 + 4t + 1}dt\). The integral simplifies to \(3\int(t^6 - 9t^2 - 18t^3 - 9t^4)\sqrt{t^4 + 4t^2 + 4t + 1}dt\). The user expresses uncertainty about solving the integral, indicating it appears more complex than previous examples encountered in class.

PREREQUISITES
  • Understanding of line integrals in calculus
  • Familiarity with parametric equations
  • Knowledge of differential arc length calculation
  • Experience with integral calculus techniques
NEXT STEPS
  • Research techniques for solving complex integrals, particularly those involving parametric equations
  • Study the properties of line integrals in vector calculus
  • Learn about numerical integration methods for approximating difficult integrals
  • Explore the use of computer algebra systems like Wolfram Alpha for integral evaluation
USEFUL FOR

Students studying calculus, particularly those focusing on line integrals and parametric equations, as well as educators seeking to enhance their teaching methods in integral calculus.

etotheix
Messages
21
Reaction score
0

Homework Statement



Evaluate the following line integral on the indicated curve C

\int(y^2-x^2)ds

C: x = 3t(1+t), y=t^3 ; 0 <= t <= 2

Homework Equations



ds = \sqrt{(f&#039;(t))^2+(g&#039;(t))^2}dt

The Attempt at a Solution



dx/dt = 3+6t
dy/dt = 3t^2

ds = \sqrt{(3+6t)^2+(3t^2)^2}dt
ds = 3*\sqrt{t^4+4t^2+4t+1}dt

y^2 = t^6
x^2 = (3t+3t^2)^2 = 9t^2+18t^3+9t^4

\int(y^2-x^2)ds = 3\int(t^6-9t^2-18t^3-9t^4)\sqrt{t^4+4t^2+4t+1}dt

From here I don't know how to solve the integral, and it looks way more complicated than what we have done so far in class. Maybe I am doing something wrong? Or there is a trick involved here? Any help would be greatly appreciated. Thanks.
 
Last edited:
Physics news on Phys.org
I see a typo, but I can't offer any more help than that.
\int(y^2-x^2)ds = 3\int(t^6 -9t^2-18t^3-9t^4)\sqrt{t^4+4t^2+4t+1}dt
 
Thanks Mark44, I corrected the mistake in the first post. I will come back to this thread if I find an answer and post it.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
1K
Replies
12
Views
2K
  • · Replies 10 ·
Replies
10
Views
1K
Replies
2
Views
1K
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 105 ·
4
Replies
105
Views
7K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
6
Views
2K