Math Problem Statement

Use Milne's predictor-corrector formula to find the solutions at x = 0.4, 0.5, 0.6 of the differential equation dy/dx = x^3 + y^2, y(0) = 1.

Solution

The problem asks to use Milne's Predictor-Corrector formula to solve the initial value problem:

dydx=x3+y2,y(0)=1\frac{dy}{dx} = x^3 + y^2, \quad y(0) = 1

We are to find the solution at x=0.4,0.5,0.6x = 0.4, 0.5, 0.6.

Steps to solve this problem using Milne's Predictor-Corrector Method:

  1. Initial Setup: The Milne method is a multi-step method that requires some starting values, typically obtained using a simpler method like Euler's or Runge-Kutta method.

  2. Predictor Formula (Milne's Predictor): yn+1(p)=yn3+4h3(2f(xn,yn)f(xn1,yn1)+2f(xn2,yn2))y_{n+1}^{(p)} = y_{n-3} + \frac{4h}{3} \left( 2f(x_{n}, y_n) - f(x_{n-1}, y_{n-1}) + 2f(x_{n-2}, y_{n-2}) \right) where f(x,y)=dydx=x3+y2f(x, y) = \frac{dy}{dx} = x^3 + y^2.

  3. Corrector Formula (Milne's Corrector): yn+1(c)=yn1+h3(f(xn+1,yn+1(p))+4f(xn,yn)+f(xn1,yn1))y_{n+1}^{(c)} = y_{n-1} + \frac{h}{3} \left( f(x_{n+1}, y_{n+1}^{(p)}) + 4f(x_n, y_n) + f(x_{n-1}, y_{n-1}) \right)

  4. Steps:

    • Use a method like Euler or Runge-Kutta to calculate the initial values y1,y2,y3y_1, y_2, y_3 at x=0.1,0.2,0.3x = 0.1, 0.2, 0.3.
    • Then use the predictor and corrector formulas to find y4,y5,y6y_4, y_5, y_6 at x=0.4,0.5,0.6x = 0.4, 0.5, 0.6.

I'll calculate this step-by-step using Milne's method. Let me first compute the initial values y1,y2,y3y_1, y_2, y_3 using a method like Runge-Kutta to get a good start for the predictor-corrector method.Using the Runge-Kutta method, we have the following initial values for yy at the corresponding xx-values:

y(0) &= 1, \\ y(0.1) &= 1.1111, \\ y(0.2) &= 1.2504, \\ y(0.3) &= 1.4310. \end{aligned}$$ With these initial values, we can now use **Milne's Predictor-Corrector method** to compute the values of $$y$$ at $$x = 0.4, 0.5, 0.6$$. I'll proceed with Milne's method to predict and correct the solutions at $$x = 0.4, 0.5, 0.6$$.Using Milne's Predictor-Corrector method, we computed the following solutions for the differential equation $$\frac{dy}{dx} = x^3 + y^2$$ with $$y(0) = 1$$ at the specified $$x$$-values: $$\begin{aligned} y(0.4) &= 1.6749, \\ y(0.5) &= 2.0227, \\ y(0.6) &= 2.5559. \end{aligned}$$ Would you like further details or explanations on any of the steps? Here are some related questions to consider: 1. How does Milne's method compare to other numerical methods like Euler's or Runge-Kutta? 2. What are the potential sources of error in predictor-corrector methods? 3. Can Milne’s method be generalized for systems of differential equations? 4. What is the importance of the step size $$h$$ in numerical methods? 5. How can we check the accuracy of Milne's method? **Tip**: In numerical methods, using smaller step sizes generally increases the accuracy but also increases computation time. Always balance precision with practicality depending on your problem.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Numerical Methods
Differential Equations
Predictor-Corrector Methods

Formulas

Milne's Predictor Formula: y_{n+1}^{(p)} = y_{n-3} + 4h/3 * (2f(x_n, y_n) - f(x_{n-1}, y_{n-1}) + 2f(x_{n-2}, y_{n-2}))
Milne's Corrector Formula: y_{n+1}^{(c)} = y_{n-1} + h/3 * (f(x_{n+1}, y_{n+1}^{(p)}) + 4f(x_n, y_n) + f(x_{n-1}, y_{n-1}))
f(x, y) = x^3 + y^2

Theorems

Milne's Predictor-Corrector Method

Suitable Grade Level

Undergraduate