General Solution for a Bernoulli Equation with Trigonometric Functions

In summary, the conversation was about finding the general solution of a differential equation. The equation involved a Bernoulli equation with variables for p(x) and g(x). The person attempting to solve the equation used a change of variables and got to the general solution, but got confused when trying to solve an integral. After some struggle, they were able to figure out the solution.
  • #1
muso07
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Homework Statement


Find the general solution of the following differential equation.
y'+4xy=10xy2cos(x2)

Homework Equations


The usual Bernoulli equation ones:
y'+p(x)y = g(x)ya
u(x)=[y(x)]1-a
u'+(1-a)pu = (1-a)g

The Attempt at a Solution


I got up until the general solution part.. I'll just type bits of it out because it'll take me ages (I'm a slow typer).

So in the equation, a=2, p(x)=4x, g(x)=10xcos(x2)

Change of variables:
u(x)=[y(x)]1-a = y-1

and u'+(1-a)pu = (1-a)g
=> u'-4xu = -10xcos(x2)

Now here's where I get confused..
General solution:
u= e[tex]\int[/tex]p(x)dx[[tex]\int[/tex]r(x)e[tex]\int[/tex]p(x)dxdx+c
where p=-4x, r=-10xcos(x2)

u= e[tex]\int[/tex]-2x^2[[tex]\int[/tex](-10xcos(x2)e[tex]\int[/tex]-2x^2)dx+c

Argh.. that's messy, I hope it makes sense.

Anyway, I can't seem to figure out that integral... I've used parts and stuff but I don't seem to be getting anywhere.

Any help would be appreciated.
 
Last edited:
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  • #2
Nevermind, I figured it out.
 

What is the Bernoulli equation with trig?

The Bernoulli equation with trig is a mathematical equation that relates the pressure, velocity, and height of a fluid flowing in a closed system. It takes into account the effects of gravity and the trigonometric functions sine and cosine.

How is the Bernoulli equation with trig derived?

The Bernoulli equation with trig is derived from the Bernoulli equation, which states that the total energy of a fluid remains constant. The addition of trigonometric functions allows for the effects of gravity to be included in the equation.

What is the significance of the Bernoulli equation with trig in fluid mechanics?

The Bernoulli equation with trig is a fundamental tool in fluid mechanics, as it allows for the prediction of flow behavior and the calculation of various parameters such as pressure and velocity. It is used in a wide range of applications, from aerodynamics to hydraulics.

What are the assumptions made in the Bernoulli equation with trig?

The Bernoulli equation with trig makes several assumptions, including that the fluid is incompressible, the flow is steady and laminar, and there are no external forces acting on the fluid.

What are some real-world applications of the Bernoulli equation with trig?

The Bernoulli equation with trig is used in various real-world applications, such as calculating the lift and drag of an airplane wing, designing water turbines, and predicting the flow of blood in the human body. It is also used in the construction of pipes and channels for efficient fluid flow.

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