## Taylor Expansion, and proving the second derivative??

Im sure this is not a hard question but can you help me I just start it with a numerical method class.

a) show that second derivative at Xo can be expressed as:

$f''(Xo) = 1/h^2 [f(Xo-h)-2f(Xo+h)]-h^2/12*f^4(epsilon)$
and what means epsilon??

regards,
Alexis