If y = x ^ n + ( 1 / x ^ n )

prove that

( x^2y'' ) + ( xy' ) - ( n^2y ) = 0

2 answers

y = xn + x-n
y' = nxn-1 - nx-n-1
y'' = n(n-1)xn-2 + n(n+1)x-n-2

x2y'' + xy' - n2y
= n(n-1)xn + n(n+1)x-n + nxn - nx-n - n2xn - n2x-n
= 0
thank u so much
i realised that i had the correct answer but wasn't sure about the signs