1. Limited time only! Sign up for a free 30min personal 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!

Compute dx (electric field)

  1. Oct 1, 2009 #1
    1. The problem statement, all variables and given/known data
    This is part of a find the electric field problem. I've narrowed down the part I find confusing.

    Consider a right triangle, with legs of length x and R. Angle θ is opposite x. Leg x is a segment of a ray starting where lines x and R intersect. There is a differential length dx along line x (it is at a vertex of the right triangle). Find dx in terms of R and θ.

    2. Relevant equations
    standard trig functions, pythagorean theorem?

    3. The attempt at a solution
    The answer according to the solutions manual is dx = (R/cos^2 θ) dθ. Obviously, I cannot understand at all where that came from.

    I did get R tan ( θ + dθ) = x + dx but that isn't very helpful either
    Last edited: Oct 1, 2009
  2. jcsd
  3. Oct 2, 2009 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    It sounds like R is fixed, while x and θ can vary.

    Can you write an expression for x in terms of R and θ?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Compute dx (electric field)