Question

Im trying to find the general solution of y'''' - y = 0. I found the roots to be lamda = 0 and lamda = 1 but apparently this isnt right. Any chance anybody knows what im doing wrong?

Answer 1

When you create the characteristic polynomial you get:\[y^{''''}-y=0\Longrightarrow \lambda^4-1=0\]

Answer 2

or is that four apostrophes?

Answer 3

i had to glance twice too, its 4.

Answer 4

four? so yeah lambda ^4 =1
lambda = +/- 1

Answer 5

ooooooooooooh. Thank you. I put the characteristic equation as lamda^4-lamda = 0. Instead of -1. Silly mistake. Thank you!