Results 1 to 2 of 2

Math Help - Vector-Valued functions

  1. #1
    Newbie
    Joined
    Feb 2010
    Posts
    20

    Vector-Valued functions

    Hello everyone.

    I need to solve this math problem and it has been giving me lots of trouble.

    Find all values of t such that r'(t) is parallel to the xy-plane.

    r(t)=<sqrt(t+1), cos(t), t^4-8t^2>

    Thanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Behold, the power of SARDINES!
    TheEmptySet's Avatar
    Joined
    Feb 2008
    From
    Yuma, AZ, USA
    Posts
    3,764
    Thanks
    78
    Quote Originally Posted by palmaas View Post
    Hello everyone.

    I need to solve this math problem and it has been giving me lots of trouble.

    Find all values of t such that r'(t) is parallel to the xy-plane.

    r(t)=<sqrt(t+1), cos(t), t^4-8t^2>

    Thanks!

    The normal vector to the xy-plane is \hat{k}.

    Whe the normal of the plane is perpenduclar to r'(t)
    the vector will be parallel to the plane.
    So when \hat{r}'(t)\cdot \hat{k}=0 \iff 4t^3-16t=0.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Sketching vector-valued functions
    Posted in the Calculus Forum
    Replies: 4
    Last Post: February 21st 2011, 03:53 AM
  2. [SOLVED] Vector-valued functions and motion in space #2
    Posted in the Calculus Forum
    Replies: 1
    Last Post: September 17th 2010, 10:33 AM
  3. [SOLVED] Vector-valued functions and motion in space
    Posted in the Calculus Forum
    Replies: 3
    Last Post: September 17th 2010, 08:56 AM
  4. Vector-Valued Functions
    Posted in the Calculus Forum
    Replies: 1
    Last Post: March 4th 2009, 05:40 PM
  5. vector valued functions
    Posted in the Calculus Forum
    Replies: 3
    Last Post: June 22nd 2008, 06:47 PM

Search Tags


/mathhelpforum @mathhelpforum