• Support PF! Buy your school textbooks, materials and every day products Here!

Unit tangent vector (cal 3)

  • Thread starter weckod
  • Start date
  • #1
13
0
positon vectors r(t) find the unit tangent vectors T(t) for the given value of t

r(t) = (cos5t, sin5t)
T(pi/4) = ( , )

r(t) = (t^2, t^3)
T(1) = ?

r(t) = e^5t i + e^-1t j + t k
T(2) = ? i+ ? j+ ? k

now the to find it i use r'(t)/lr'(t)l
I did that, but i get wrong answers i dont know what im doing wrong cuz all i c is that is how u find the unit tangent vectors... someone plz help me and explain what u did.. thanks alot!
 

Answers and Replies

  • #2
382
2
the derivative is the tangent vector.
then divide it by its magnitude to get unit tangent vector.
 
  • #3
13
0
I did that and the damn computer say i got the wrong answers.... like the 1st one i took it derivative then i divid it by its magnitude which is squaring everything and sq rt it right thats what i did..
 
  • #4
382
2
give the answer that you have found for the first one.
 
  • #5
13
0
well i worked out the second one i got (1, 1) i really im doin something stupid
 
  • #6
382
2
i get 2/sq rt of 13, 3/ sq rt of 13
what is wrong with your steps?
 

Related Threads for: Unit tangent vector (cal 3)

Replies
2
Views
240
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
14
Views
845
  • Last Post
Replies
1
Views
10K
  • Last Post
Replies
1
Views
467
Replies
1
Views
2K
  • Last Post
Replies
8
Views
2K
  • Last Post
Replies
3
Views
2K
Top