Results 1 to 2 of 2

Math Help - How l33t are you at differentiating??

  1. #1
    tedz0r
    Guest

    Tough PUzzle

    Heres some quality problem solving for anyone who wishes to have a go

    A sine function is such that when u differentiate it, the resulting function has an amplitude twice the original function. If the original function passes through (PI/6,0) and the derivative passes through (7PI/6,0) find a possible sine function.
    Last edited by tedz0r; October 2nd 2005 at 02:02 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Nov 2005
    Posts
    21
    I'm not sure how general a "sine function" can be, but I'll try this: A*sin(B+C*x).
    The first condition implies that C=2.
    The second condition implies that sin(B+Pi/3)=0, so B+Pi/3=2*Pi*n for any integer n; I'll try n=0, so B=-Pi/3.
    The third condition implies that 0=2A*cos(7Pi/3-Pi/3)=2A*cos(2*Pi)=2A, so A=0.
    Therefore, the ONLY possibility is the zero function.

    In general, when you have N parameters and N conditions, the parameters are uniquely determined by the conditions.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need help differentiating
    Posted in the Calculus Forum
    Replies: 1
    Last Post: December 28th 2010, 08:08 AM
  2. Help differentiating sin(x)^x
    Posted in the Calculus Forum
    Replies: 11
    Last Post: November 12th 2010, 08:40 AM
  3. Differentiating (tan (sin x))^2
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 12th 2010, 05:41 PM
  4. Differentiating
    Posted in the Calculus Forum
    Replies: 4
    Last Post: December 2nd 2008, 05:29 AM
  5. Differentiating
    Posted in the Calculus Forum
    Replies: 3
    Last Post: December 1st 2008, 12:10 PM

/mathhelpforum @mathhelpforum