Sounds like you are trying to move submarines or aircraft ( I guess).
I hope you have looked at the post from riis, 'cause you MUST convert your angles to radians, otherwise all trig formulas wil fail.

We are waiting for some more explanation on what you're trying to do, that would make helping you more easy

BTW I'm working with a 2D modell to move ship's, see my code for 2D movements
VB Code:
  1. Public Sub Bewegung(PosX, PosY, Course, Speed)

  2. 'Movement of an object using course (0-359) and speed(Kn) for 1 second

  3. 'Input PosX, PosY,Course, Speed

  4. 'Output PosX ,PosY

  5. PosX = Sin(Course * 1.74532925199433E-02) * Speed * (1 / 3600) + PosX

  6. PosY = Cos(Course * 1.74532925199433E-02) * Speed * (1 / 3600) + PosY

  7. End Sub