Differential equations and series

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SUMMARY

The discussion focuses on solving the initial value problem defined by the differential equation y'' - xy' - 2y = 4x^2 with initial conditions y(0) = 1 and y'(0) = 1 using power series. The user attempted to express the solution as a power series C_n x^n, differentiated it, and substituted it into the equation. The key insight is that the coefficient of x^2 on the left-hand side must equal 4, while all other coefficients must equal zero, leading to a system of equations that must be solved for the coefficients C_n.

PREREQUISITES
  • Understanding of power series expansions
  • Familiarity with differential equations, specifically second-order linear equations
  • Knowledge of initial value problems and their solutions
  • Ability to manipulate series and coefficients in algebraic expressions
NEXT STEPS
  • Study the method of power series solutions for differential equations
  • Learn how to derive coefficients from power series by equating terms
  • Explore the theory behind initial value problems in differential equations
  • Practice solving similar differential equations with different initial conditions
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Students and educators in mathematics, particularly those focusing on differential equations, as well as anyone seeking to enhance their problem-solving skills in calculus and series analysis.

freshman2013
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1.

1.Homework Statement


Use power series to evaluate intial value problem y''-xy'-2y=4x^2 y(0)=1 and y'(0)=1

Homework Equations

The Attempt at a Solution


I got the series Cnx^n and took its derivative and plugged it into the formula and I got but when I factor out x^n and set that experssion equal to 4x^2, I realize I'm stuck and I'm not sure If I'm doing it correctly.
 
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freshman2013 said:
1.

1.Homework Statement


Use power series to evaluate intial value problem y''-xy'-2y=4x^2 y(0)=1 and y'(0)=1

Homework Equations




The Attempt at a Solution





I got the series Cnx^n and took its derivative and plugged it into the formula and I got but when I factor out x^n and set that experssion equal to 4x^2, I realize I'm stuck and I'm not sure If I'm doing it correctly.

What that tells you is that coefficient of [itex]x^2[/itex] on the left hand side is 4, and the coefficient of every other power of [itex]x[/itex] on the left hand side is zero.
 

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