
Differential Equations Ordinary and Partial Differential Equations Math Forum 
 LinkBack  Thread Tools  Display Modes 
March 21st, 2019, 04:26 AM  #1 
Newbie Joined: Jul 2018 From: Australia Posts: 2 Thanks: 0  Help classifying DEs
I need help classifying the following differential equations as:  linear  Bernoulli equation  separable  exact  homogeneous  both linear and exact  both linear and separable  both Bernoulli and separable a) $\displaystyle dy/dx = y^2/x^2  x/y$ (My answer: homogeneous) b) $\displaystyle dy/dx = x/y  2. y^3/x^3$ (My answer: homogeneous) c) $\displaystyle (3x^2  2y^2  ½\cdot y\cdot\cos x) dx + (4xy  ½\cdot\sin x) dy = 0$ (My answer: exact) I am not sure if my answers are correct or if there are more options. Thanks for any advice. Last edited by skipjack; March 22nd, 2019 at 03:28 AM. 
March 22nd, 2019, 03:37 AM  #2 
Global Moderator Joined: Dec 2006 Posts: 20,484 Thanks: 2041 
(a) and (b) are first order, nonlinear, homogeneous, nonseparable ordinary differential equations. Why did you think (c) is exact? 

Tags 
classifying, des 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Classifying Functions  Math_Junkie  Calculus  12  October 3rd, 2009 03:22 PM 
Markov chain and classifying states  BrainMan  Advanced Statistics  0  March 16th, 2009 04:41 PM 
Classifying PDEs as elliptic, parabolic and hyperbolic help  fzeropro  Applied Math  2  July 20th, 2008 03:20 AM 