Undetermined coefficient method

  • Thread starter Thread starter masterchiefo
  • Start date Start date
  • Tags Tags
    Coefficient Method
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 1K views
masterchiefo
Messages
211
Reaction score
2

Homework Statement


y''+10y'+25y=x+2+3e-5*x

Homework Equations

The Attempt at a Solution


F(D) = D2+10D+25 zeroes: -5
yc= C1*e-5*x + C2*e-5*x *x

yp = ax+b + C*e-5*x
yp = ax+b + C*e-5*x*x2

I just want to know if my yc and yp is correct, after that I know how to do it.
 
Physics news on Phys.org
yc is correct, yp is not. The SECOND yp, [itex]ax+ b+ cx^2e^{-5x}[/itex] is correct. Since [itex]e^{-5x}[/itex] and [itex]xe^{-5x}[/itex] satisfy the associated homogenous equation you need the "[itex]x^2[/itex]".