The solution to the Differential Equation

In summary, the initial value problem y' - (3/t)y = 0 with y(1) = -10 has the solution y = -Ct/3, where C is a constant, and the integrating factor is u(t) = t^-3. The missing step in the solution was integrating 1/t, which gives t^-3 as the integrating factor.
  • #1
Northbysouth
249
2

Homework Statement


The Initial value problem:

y' - (3/t)y = 0

y(1) = -10

Has the solution:

I have attached an image of the question


Homework Equations





The Attempt at a Solution



Firstly I found the integrating factor:

u(t) = e∫-3/t dt

u(t) = -3/t

I plugged this back into the original equation:

(-3/t)y' + (9/t2y = 0

∫[-(3/t)y]' dt = ∫ 0 dt

(-3/t)y = C

y = -Ct/3

But I don't understand where I go from here. The possible answers all include t3 and I don't understand where that has come from. What step did I miss?
 

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  • #2
Northbysouth said:

Homework Statement


The Initial value problem:

y' - (3/t)y = 0

y(1) = -10

Has the solution:

I have attached an image of the question


Homework Equations





The Attempt at a Solution



Firstly I found the integrating factor:

u(t) = e∫-3/t dt

u(t) = -3/t

What is the integration of 1/t?
 
  • #3
Yes, I see my mistake now.

u(t) = t^-3
 

FAQ: The solution to the Differential Equation

What is a differential equation?

A differential equation is a mathematical equation that relates a function to its derivatives. It describes how a quantity changes over time or space, and is commonly used to model various physical phenomena.

Why are differential equations important?

Differential equations are important because they provide a mathematical framework for understanding and predicting natural phenomena. They are used in many fields of science, including physics, chemistry, biology, and economics.

What is the solution to a differential equation?

The solution to a differential equation is a function that satisfies the equation. It represents the behavior of the system being modeled and can be used to make predictions about the system's future behavior.

How do you solve a differential equation?

There are various methods for solving differential equations, depending on the type of equation and its complexity. Some common techniques include separation of variables, substitution, and using integral transforms.

Can all differential equations be solved?

No, not all differential equations can be solved analytically. In some cases, the solution may be too complex or impossible to find using known methods. In these cases, numerical methods can be used to approximate the solution.

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