Find t in a Parametric Equation

  • Thread starter Thread starter Jimerd
  • Start date Start date
  • Tags Tags
    Parametric
Click For Summary
To find the value of t for the parametric equations x = 6 cos t, y = 6 sin t, and z = 6 cos 2t at the point (3√3, 3, 3), the equations must be solved simultaneously. The equations yield cos t = √3/2 and sin t = 1/2, which correspond to t = π/6. The z-coordinate equation, 6 cos 2t = 3, simplifies to cos 2t = 1/2, leading to 2t = π/3 or 5π/3, thus t = π/6 or 5π/6. The tangent line can then be determined using the derivative r'(t) evaluated at t = π/6. The discussion focuses on solving for t to establish the tangent line's parametric equations.
Jimerd
Messages
5
Reaction score
0

Homework Statement


Find parametric equations for the tangent line to the curve with the given parametric equations at the specified point.

x = 6 cos t, y = 6 sin t, z = 6 cos 2t; (3√3, 3, 3)

Homework Equations





The Attempt at a Solution



So I understand that r(t)= 6cost t, 6sint, 6cos2t

and r'(t)= -6sint, 6cost, -12sin2t

So here is the questions, how do I find what the value of t is at points (3√3, 3, 3)
 
Physics news on Phys.org
Jimerd said:

Homework Statement


Find parametric equations for the tangent line to the curve with the given parametric equations at the specified point.

x = 6 cos t, y = 6 sin t, z = 6 cos 2t; (3√3, 3, 3)

Homework Equations



The Attempt at a Solution



So I understand that r(t)= 6cost t, 6sint, 6cos2t

and r'(t)= -6sint, 6cost, -12sin2t

So here is the questions, how do I find what the value of t is at points (3√3, 3, 3)
Solve (6cost t, 6sint, 6cos2t) = (3√3, 3, 3) for t .
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 11 ·
Replies
11
Views
3K
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K