Differential equations question

In summary, the equation dx/dt = t/(x*t^2+x^3) can be simplified using the substitution u = t^2 to obtain the equation du/dx = 2u/(ux+x^3). However, this does not provide a straightforward solution as we cannot separate u and x. Using an integrating factor, the problem can be solved easily as it is a linear equation.
  • #1
nocloud
12
0
i have this equation:
dx/dt = t/(x*t^2+x^3)

using the substitution u = t^2, i obtain the following equation:

du/dx = 2u/(ux+x^3)

does anybody know how i can solve this equation?
 
Physics news on Phys.org
  • #2
nocloud said:
i have this equation:
dx/dt = t/(x*t^2+x^3)

using the substitution u = t^2, i obtain the following equation:

du/dx = 2u/(ux+x^3)

does anybody know how i can solve this equation?
No, you don't obtain that equation. If u= t^2, then dx/dt= dx/du du/dt=2t dx/du.
The equation becomes 2t dx/du= t/(xu+ x^3) or dx/du= 1/(2(xu+x^3). Then
du/dx= 2(xu+ x^3). Unfortunately, since we still cannot separate u and x, that doesn't really help.
 
  • #3
ah, my bad,

okay, this problem is now very easy then since its linear and i can just use an integrating factor
 

FAQ: Differential equations question

What are differential equations?

Differential equations are mathematical equations that relate a function with its derivatives. They are used to model many real-world phenomena, such as growth and decay, motion, and electrical circuits.

What is the difference between ordinary and partial differential equations?

Ordinary differential equations involve a single independent variable, while partial differential equations involve multiple independent variables. Ordinary differential equations are used to model phenomena that change over time, while partial differential equations are used to model phenomena that vary over space.

How are differential equations solved?

Differential equations can be solved through analytical methods, such as separation of variables or using integrating factors. They can also be solved numerically using methods such as Euler's method or Runge-Kutta methods.

What are some applications of differential equations?

Differential equations have a wide range of applications in physics, engineering, economics, and biology. They are used to model population growth, heat transfer, fluid dynamics, and many other phenomena.

Are there any real-life examples of differential equations?

Yes, there are many real-life examples of differential equations. Some common examples include the motion of a pendulum, the spread of diseases in a population, and the cooling of a cup of coffee. Differential equations are also used in engineering to design bridges, airplanes, and other structures.

Back
Top