Math Problem Statement

The iterative formula below will give an approximate solution to the equation x^3 + 2x^2 - 3x = 12. Use this formula to work out an approximate solution to the equation, starting with x1 = 0. Give your answer to 3 d.p. Also, calculate the difference between x^3 + 2x^2 - 3x and 12 at your approximate solution.

Solution

Let's solve the given problem step by step:


a) Use the iterative formula to find an approximate solution (starting with x1=0x_1 = 0).

The iterative formula is: xn+1=3xn+12xn+2x_{n+1} = \sqrt{\frac{3x_n + 12}{x_n + 2}} Starting with x1=0x_1 = 0, we'll compute successive iterations until the result stabilizes to 3 decimal places.

b) Calculate the difference between x3+2x23xx^3 + 2x^2 - 3x and 12 at the approximate solution found in part (a).

I will compute this now. math

Iterative formula function

def iterative_formula(x_n): return math.sqrt((3 * x_n + 12) / (x_n + 2))

Start with x1 = 0 and compute iterations

x_values = [0] # Initial guess tolerance = 0.001 # Stop when the change is less than this

while True: x_next = iterative_formula(x_values[-1]) x_values.append(x_next) if abs(x_next - x_values[-2]) < tolerance: break

Rounded result to 3 decimal places

approx_solution = round(x_values[-1], 3)

Part b: Calculate difference at the approximate solution

def calculate_difference(x): return abs((x3 + 2 * x2 - 3 * x) - 12)

difference = round(calculate_difference(approx_solution), 3)

approx_solution, difference### Results: a) The approximate solution to 3 decimal places is x=2.112x = 2.112.
b) The difference between x3+2x23xx^3 + 2x^2 - 3x and 12 at x=2.112x = 2.112 is 0.0060.006.


Would you like detailed steps for the iterative process or calculations?
Here are 5 related questions you might consider next:

  1. What happens if the initial guess is different (e.g., x1=1x_1 = 1)?
  2. How is the convergence rate of this iterative method determined?
  3. Can we prove mathematically that the solution converges using this formula?
  4. What happens if we use more decimal places in intermediate calculations?
  5. How does this result compare to solving the equation using other methods, like Newton-Raphson?

Tip: Iterative methods are sensitive to starting values. Choosing a good initial guess can significantly speed up convergence!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Iteration
Approximation
Algebraic Equations

Formulas

x_{n+1} = sqrt((3x_n + 12)/(x_n + 2))
x^3 + 2x^2 - 3x = 12

Theorems

Convergence of Iterative Sequences

Suitable Grade Level

Grades 10-12