1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Discrete Math Help Urgent Pls =)

  1. Jan 5, 2005 #1
    How do you find the angle between the co-ordinate axis (i.e. the xz plane) and another plane in general?
     
  2. jcsd
  3. Jan 5, 2005 #2

    learningphysics

    User Avatar
    Homework Helper

    Angle between two planes is the angle between the normals of the planes.
     
  4. Jan 5, 2005 #3

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Expanding on what learningphysics said, if one plane is given by Ax+ By+ Cz= D and the other by ax+ by+cz= d, then the normal vectors are Ai+ Bj+ Ck and ai+ bj+ ck respectively. u.v= |u||v|cos(θ) so θ, the angle between the two vectors and the angle between the planes, is given by cos(θ)= u.v/(|u||v|).


    In particular, the xz-plane has normal vector j. If the other plane is given by Ax+By+Cz= D, its normal vector is Ai+Bj+Ck. The dot product of those is simply B so the angle between the planes is given by [itex]cos(\theta)= \frac{B}{\sqrt{A^2+B^2+C^2}}[/itex].
     
    Last edited: Jan 5, 2005
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Discrete Math Help Urgent Pls =)
  1. Discrete Math Help (Replies: 3)

  2. Discrete Math Help (Replies: 1)

Loading...