Verifying a Power Series Solution for y''-4y=0

[joker2014]

Homework Statement

substitute the given power series below into ODE y'' -4y=0 to verify it is a solution

Homework Equations

y=∑ 2ⁿ xⁿ / n!
n=0

y''-4y=0

The Attempt at a Solution

I have absolutely no idea how start.

 

[fourier jr]

you must know the derivative of $x^n$ by now. that's somewhere you could start.

 

[Mark44]

Locked because no attempt was shown.