Solving Derivative Problem: Find Constants A, B & C

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SUMMARY

The discussion focuses on solving the differential equation \(y'' + y' - 2y = x^2\) by finding constants A, B, and C in the quadratic function \(y = Ax^2 + Bx + C\). The user correctly identifies the derivatives \(y' = 2Ax + B\) and \(y'' = 2A\), leading to the equation \(y'' + y' - 2Ax^2 - 2Bx - 2C = x^2\). To solve for A, B, and C, one must equate coefficients of like powers of x, ensuring that the coefficients of \(x^1\) sum to zero and the constant terms are balanced.

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Homework Statement


Find the constants A, B, and C such that the function [tex]y=Ax^{2}+Bx+C[/tex] satisfies the differential equation [tex]y^{''}+y^{'}-2y=x^{2}[/tex].



The Attempt at a Solution


I know that [tex]y^{''}+y^{'}-2Ax^{2}-2Bx-2C=x^{2}[/tex] and that [tex]y^{'}=2Ax+B[/tex] and [tex]y^{''}=2A[/tex], but I'm really stuck at this point. Any help would be appreciated.
 
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almost there, substitute in for y & y'

each power of x will give you an equation that must be solved for the solution to satisfy the differential equation

eg. the co-efficients of x^1 must add up to zero
 

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