MathDB
Putnam 1979 B4

Source:

April 8, 2022
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Problem Statement

(a) Find a solution that is not identically zero, of the homogeneous linear differential equation (3x2x1)y(9x2+9x2)y+(18x+3)y=0.(3x^2-x-1)y''-(9x^2+9x-2)y'+(18x+3)y=0. Intelligent guessing of the form of a solution may be helpful.
(b) Let y=f(x)y=f(x) be the solution of the nonhomogeneous differential equation (3x2x1)y(9x2+9x2)y+(18x+3)y=6(6x+1)(3x^2-x-1)y''-(9x^2+9x-2)y'+(18x+3)y=6(6x+1) that has f(0)=1f(0)=1 and (f(1)2)(f(1)6)=1.(f(-1)-2)(f(1)-6)=1. Find integers a,b,ca,b,c such that (f(2)a)(f(2)b)=c.(f(-2)-a)(f(2)-b)=c.