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Friday, July 25, 2014

Solving Equations - Homogeneous Functions, 13

Category: Differential Equations

"Published in Newark, 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? The algebraic functions are the combination of x and y in the group 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

 

Thursday, July 24, 2014

Separation of Variables, 20

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 y(1 + e2x) 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

 

Wednesday, July 23, 2014

Separation of Variables, 19

Category: Differential Equations

"Published in Newark, California, USA"

Find the general solution for


Solution:

Consider the given equation above 


Transfer all the terms from the right side of the equation to the left side of the equation and group as follows







In order to separate dx and dy from other variables, divide both sides of the equation by x²y² as follows
 
 
 
   
Integrate both sides of the equation, we have






Therefore, the general solution is