Calculating Polar Curve Length with Period of 3π: r = psin3(θ/3)

In summary, The length of the polar curve r = psin3(\theta/3) can be found by using the equation L = \intsqrt(f(\theta)2 + f'(\theta)2)d\theta and taking into consideration the hint that the period of the curve is 3\pi. The variable p should be treated as a constant in this problem.
  • #1
Snoogx
22
0

Homework Statement


Find the length of the polar curve r = psin3([tex]\theta[/tex]/3)
Hint: The period of the curve is 3[tex]\pi[/tex]

Homework Equations


L = [tex]\int[/tex]sqrt(f([tex]\theta[/tex])2 + f'([tex]\theta[/tex])2)d[tex]\theta[/tex]

The Attempt at a Solution


I know from the hint that 0[tex]\leq[/tex][tex]\theta[/tex][tex]\geq[/tex]3[tex]\pi[/tex]

The only problem I have is how do I start this with "p" in the r-equation. Do I treat it as another variable or is it a constant?
 
Physics news on Phys.org
  • #2
I would treat p as a constant, you're not given necessary information to solve the problem if it were not.
 
  • #3
If p were not a constant, the equation would not define a curve.
 

1. What is the definition of length of polar curve?

The length of a polar curve is the distance along its arc from the starting point to the ending point. It can also be thought of as the total distance traveled by a point on the curve as the angle of rotation changes.

2. How is the length of a polar curve calculated?

The length of a polar curve is calculated using the arc length formula: L = ∫√(r² + (dr/dθ)²)dθ, where r is the polar equation and dr/dθ is the derivative of r with respect to θ. This integral is evaluated from the starting angle to the ending angle of the curve.

3. What is the significance of finding the length of a polar curve?

Finding the length of a polar curve is important in various applications, such as engineering, physics, and mathematics. It can help in determining the distance traveled by an object along a curved path, or the amount of material needed to create a particular shape.

4. Can the length of a polar curve be negative?

No, the length of a polar curve cannot be negative. It represents a physical distance and therefore must be a positive value.

5. Are there any shortcuts or tricks to finding the length of a polar curve?

Yes, for certain polar curves with special properties, there are shortcuts or tricks that can be used to find their length. For example, for a cardioid curve with equation r = a(1 + cosθ), the length can be calculated as L = 8a. However, these shortcuts only apply to specific types of curves and cannot be generalized.

Similar threads

Replies
7
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
829
  • Calculus and Beyond Homework Help
Replies
3
Views
279
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
657
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
7
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
563
  • Calculus and Beyond Homework Help
Replies
8
Views
876
Back
Top