Free counters!

Wednesday, July 16, 2014

Separation of Variables, 16

Category: Differential Equations

"Published in Newark, California, USA"

Find the general solution for 


Solution:

Consider the given equation above  


In order to separate dx and dy from other variables, divide both sides of the equation by (1 - x)y² as follows




Integrate both sides of the equation, we have  







Take the inverse natural logarithm on both sides of the equation, we have






Therefore, the general solution is

 

Tuesday, July 15, 2014

Variable Separation, 15

Category: Differential Equations

"Published in Newark, California, USA"

Find the general solution for


Solution:

Consider the given equation above 

  
In order to separate dx and dy from other variables, divide both sides of the equation by x3y3 as follows





Integrate both sides of the equation, we have 









where D = 2C.

Therefore, the general solution is

 

Monday, July 14, 2014

Solving Equations - Homogeneous Functions, 8

Category: Differential Equations

"Published in Vacaville, California, USA"

Find the general solution for


Solution:

Consider the given equation above  


Did you notice that the given equation cannot be solved by separation of variables? An exponential function is a combination of x and y in the function and there's no way that we can separate x and y. 

This type of differential equation is a homogeneous function. Let's consider this procedure in solving the given equation as follows
 






Let


so that


Substitute the values of y and dy to the given equation, we have   






The resulting equation can now be separated by separation of variables as follows  




Integrate on both sides of the equation, we have 







But



Hence, the above equation becomes 



Therefore, the general solution is