How Do You Solve This Bernoulli Differential Equation?

In summary, the conversation discusses a bernoulli differential equation and the process of solving it. The equation is x(dz/dx) - 3z = -3x² and the steps to solve it are explained, including a solution with a typo that is later corrected. The conversation also mentions finding the derivative of a function and how to solve equations of this type.
  • #1
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[tex]\frac{dy}{dx} - \frac{1}{x}*y + \frac{1}{y^2}*x = 0[/tex]

This is a bernoulli differential equation which follows the following procedure
http://en.wikipedia.org/wiki/Bernoulli_differential_equation
Can someone provide the full steps because somewhere I am mistaken?
 
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  • #2
See attachment :
 

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  • #3
Thank you a lot. One more question:
In ODE I reach in a place where i have that
[tex]\frac{dz}{dx}*x^3- 3x^2*z + 3x^4 = 0[/tex]

I cannot find the derivatve on that
 
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  • #4
I cannot find the derivatve on that
I cannot understand what you mean : The derivative of what function ?
Well, the equation is
x(dz/dx)-3xz = -3x²
So , solving x(dZ/dx)-3x = 0 leads to Z = C*(x^3)
Remplace C by f(x)
then z = f(x)*(x^3)
dz/dx = (x^3)*(df/dx) +3*x² f
x( (x^3)*(df/dx) +3*x² f ) -3x (x^3)*f = -3x²
(x^4)*(df/dx) = -3x²
df/dx = -3/x²
f = (3/x) + C
z = 3 x² + C (x^3)
 
  • #5
x(dz/dx)-3xz = -3x²
how did you find that?
 
  • #6
Sorry, there was a typo. The correct equation is
x(dz/dx) - 3z = -3x²
and there was other typo in my message #4.
As a consequence, my message #4 is wrong.
Nevertheless, it shows the method to solve this kind of equations.
 

FAQ: How Do You Solve This Bernoulli Differential Equation?

What is a Bernoulli Differential Equation?

A Bernoulli differential equation is a type of first-order ordinary differential equation that can be written in the form: dy/dx + P(x)y = Q(x)y^n, where n is any real number other than 0 or 1. It is a non-linear equation and has a wide range of applications in physics and engineering.

Who discovered the Bernoulli Differential Equation?

The Bernoulli differential equation was discovered by Swiss mathematician, physicist, and inventor Daniel Bernoulli in the early 18th century.

What are the applications of Bernoulli Differential Equations?

Bernoulli differential equations have various applications in physics and engineering, such as in fluid dynamics, thermodynamics, population dynamics, and economics. They can be used to model and analyze real-life situations involving exponential growth or decay, such as population growth, radioactive decay, and chemical reactions.

What is the general solution to a Bernoulli Differential Equation?

The general solution to a Bernoulli differential equation is given by y = (1/n) * (C - ∫Q(x)e^-∫P(x)dx)^(1-n), where C is the constant of integration and n is the exponent in the equation. This solution can be found using the substitution method or by using an integrating factor.

How are Bernoulli Differential Equations solved numerically?

Bernoulli differential equations can be solved numerically using various methods, such as Euler's method, the Runge-Kutta method, and the predictor-corrector method. These methods involve breaking down the differential equation into smaller, easier-to-solve steps, and then using iterative calculations to approximate the solution.

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