Calculating Arc Length of a Polar Curve

  • Thread starter Thread starter kira137
  • Start date Start date
  • Tags Tags
    Curve Length
Click For Summary
SUMMARY

The discussion focuses on calculating the arc length of the polar curve defined by the equation x^(2/3) + y^(2/3) = 1, specifically for x in the interval [0, 1]. The user attempted to derive the arc length using the formula but encountered difficulties due to incorrect differentiation and integration steps. The correct approach involves ensuring the proper formulation of y and accurately applying the arc length formula, which includes the derivative f'(x) and the integral from 0 to 1. The user was advised to revisit the equation for y to correct the exponents and ensure accurate calculations.

PREREQUISITES
  • Understanding of polar curves and their equations
  • Knowledge of calculus, specifically differentiation and integration
  • Familiarity with the arc length formula for curves
  • Ability to manipulate and simplify algebraic expressions
NEXT STEPS
  • Review the arc length formula for polar curves
  • Practice differentiation techniques for implicit functions
  • Learn about the properties of the curve x^(2/3) + y^(2/3) = 1
  • Explore numerical integration methods for complex integrals
USEFUL FOR

Students studying calculus, particularly those focusing on polar coordinates and arc length calculations, as well as educators looking for examples of common pitfalls in solving such problems.

kira137
Messages
16
Reaction score
0
Homework Statement

Find the length of the curve x^(2/3)+y^(2/3) = 1 for x in the interval [0.1].

The attempt at a solution

y = (1-x)^(2/3)
f'(x) = (4x^(-1/3) (1-x^(2/3))^(1/2))/9

then i plugged it into arc length formula
1
S sqrt(1+((4x^(-1/3) (1-x^(2/3))^(1/2))/9)^2 =
0

1
S sqrt(1+((16x^(-2/3) (1-x^(2/3))/81) =
0

1
S sqrt(1+((16x^(-2/3) -16)/81) =
0

1
S sqrt(16x^(-2/3) +65))/81 =
0

'''''''''1
1/9 S sqrt(16x^(-2/3) +65) = ...
'''''''''0

then I got stuck.. I wasn't even sure if I was solving this question the right way.
If I let u = (16x^(-2/3) +65), then whole bunch of weird numbers come out..

thank you in advance
 
Physics news on Phys.org
You started with the wrong equation for y. Exponents are wrong or missing.
 

Similar threads

  • · Replies 105 ·
4
Replies
105
Views
11K
Replies
4
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
7
Views
3K
Replies
5
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K