Math Problem Statement

Find the particular integral and complementary function

Find the particular integral and complementary function for the given differential equations.

Solution

Let's start solving the differential equations you uploaded. These are second-order linear non-homogeneous differential equations. Each one requires finding the complementary function (CF) and the particular integral (PI) to give the general solution.

1. Equation 14:

d2ydx25dydx+6y=x2\frac{d^2y}{dx^2} - 5\frac{dy}{dx} + 6y = x^2 This is a non-homogeneous equation. The general solution will be: y=yc+ypy = y_c + y_p Where:

  • ycy_c is the complementary function.
  • ypy_p is the particular integral.

Complementary Function (CF):

Solve the homogeneous equation: d2ydx25dydx+6y=0\frac{d^2y}{dx^2} - 5\frac{dy}{dx} + 6y = 0 The characteristic equation is: r25r+6=0r^2 - 5r + 6 = 0 Factor the equation: (r3)(r2)=0(r - 3)(r - 2) = 0 So, r=3r = 3 and r=2r = 2. Thus, the complementary function is: yc=C1e3x+C2e2xy_c = C_1 e^{3x} + C_2 e^{2x}

Particular Integral (PI):

For the non-homogeneous term x2x^2, we assume the form of the particular integral as: yp=Ax2+Bx+Cy_p = Ax^2 + Bx + C Substitute ypy_p into the left-hand side of the differential equation and solve for AA, BB, and CC.

After substituting and solving:

  • A=16A = \frac{1}{6}
  • B=0B = 0
  • C=0C = 0

Thus, the particular integral is: yp=x26y_p = \frac{x^2}{6}

General Solution:

The general solution is: y=yc+yp=C1e3x+C2e2x+x26y = y_c + y_p = C_1 e^{3x} + C_2 e^{2x} + \frac{x^2}{6}


Would you like me to proceed with the next equation (15), or provide details on any step?

Here are 5 related questions for further exploration:

  1. How do you determine the form of the particular integral?
  2. What happens if the non-homogeneous term is a sine or exponential function?
  3. Why is the characteristic equation important in solving differential equations?
  4. How does the method change for higher-order linear differential equations?
  5. Can you always assume a polynomial form for the particular integral?

Tip: Always check if your assumed particular integral solves the non-homogeneous part by substitution, as it helps avoid errors in solving for unknown constants.

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Math Problem Analysis

Mathematical Concepts

Differential Equations
Complementary Function
Particular Integral
Non-homogeneous Equations

Formulas

General Solution: y = y_c + y_p
Homogeneous Equation: d^2y/dx^2 + a(dy/dx) + by = 0
Characteristic Equation: ar^2 + br + c = 0
Particular Integral form based on non-homogeneous terms

Theorems

Method of Undetermined Coefficients
Superposition Principle

Suitable Grade Level

Undergraduate Math or Engineering