# Derivative of power series

1. Apr 1, 2015

### joker2014

• Member warned about posting with no effort
1. The problem statement, all variables and given/known data
substitute the given power series below into ODE y'' -4y=0 to verify it is a solution
2. Relevant equations
y=∑ 2n xn / n!
n=0

y''-4y=0
3. The attempt at a solution

I have absolutely no idea how start.

2. Apr 1, 2015

### fourier jr

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

3. Apr 1, 2015

### Staff: Mentor

Locked because no attempt was shown.