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!

Homework Help: Differential Equation

  1. May 25, 2016 #1

    chwala

    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    Solve and obtain an expression for x in terms of θ given ## (3+ cos 2θ) dx/dθ = x sin 2θ##

    2. Relevant equations


    3. The attempt at a solution
    .....##dx/x = ((sin 2θ)/(3+ cos 2θ))dθ## ,

    let ##u = (3+cos 2θ)⇒ du/dθ= -2 sin 2θ##
    thus

    ##∫dx/x = -1/2∫du/u ##...........
    are my steps correct?i can solve from here
     
  2. jcsd
  3. May 25, 2016 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    You noticed that it was 1st order seperable, and proposed a u-substitution for the resulting RHS: well done.
    I didn't check your arithmetic - you have to do that yourself - but the reasoning is sound so far.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted