Differential Equations - Initial Value Problem

In summary, the problem involves finding the derivatives of the solution to an initial value problem in an interval around x=0. The steps to solve it include getting the equation into standard form, finding the integrating factor, and using the initial condition to solve for the constant. However, the derivatives at x=0 can be found without fully solving the equation by plugging in the initial value and differentiating the equation with respect to x.
  • #1
mattbonner
14
0

Homework Statement



Suppose that the initial value problem
y' = 7(x^2) + (5y^2) − 6, y(0)=−2
has a solution in an interval about x=0.

Find y'(0) =
Find y''(0) =
Find y'''(0) =

Homework Equations



get it into standard form: dy/dt + p(t)y = g(t)
find integrating factor = e^([tex]\int[/tex]p(t)dt + k

multiply everything by integrating factor, simplify left-hand-side and then integrate both sides

using initial condition, solve for C
solve for y

The Attempt at a Solution



i don't seem to be able to get it into standard form

i tried doing y' - 5y^2 = 7x^2 -6
which gave me an integrating factor of e^-5xy

i tried following the rest of the steps with that integrating factor but its not working
 
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  • #2
You don't actually have to solve the equation to find the derivatives of y(x) at x=0. To find y'(0) just plug x=0, y=(-2) into the equation. To find the higher derivatives, just differentiate the equation with respect to x a couple of times.
 
  • #3
oh wow i feel like such a moron
thank you so much!

edit: wait, for y''(0)

i differentiated it, and i got 14x?edit(2): nvm i solved it
 
Last edited:

FAQ: Differential Equations - Initial Value Problem

What is an initial value problem?

An initial value problem (IVP) is a type of differential equation that involves finding a function or set of functions that satisfies a given equation and a set of initial conditions. The initial conditions provide the starting point for the solution of the differential equation.

What are the different types of initial value problems?

The two main types of initial value problems are ordinary differential equations (ODEs) and partial differential equations (PDEs). ODEs involve only one independent variable, while PDEs involve more than one independent variable. There are also different classifications for each type, such as linear or nonlinear, first-order or higher-order, and homogeneous or non-homogeneous.

How are initial value problems solved?

Initial value problems can be solved using various methods, including analytical techniques, such as separation of variables or the method of undetermined coefficients, and numerical techniques, such as Euler's method or the Runge-Kutta method. The method used will depend on the type and complexity of the initial value problem.

Why are initial value problems important?

Initial value problems have numerous applications in physics, engineering, and other scientific fields. They are used to model real-world phenomena, such as the motion of objects, the growth of populations, and the spread of diseases. Solving initial value problems allows us to make predictions and better understand the behavior of these systems.

What are some challenges in solving initial value problems?

One of the main challenges in solving initial value problems is finding an exact solution, as many differential equations do not have closed-form solutions. In these cases, numerical methods must be used. Another challenge is ensuring the accuracy and stability of the solution, as small errors in the initial conditions or the numerical method can lead to significant discrepancies in the solution.

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