Yes, Thank you for the help Alec. Also yes I said third, but as you can see from my variable name of yaytwo i meant second derivative, and yeah i got that working, I was still very stumped on how to work the third derivative.... I appreciate the example very much. and yes that also worked like a charm. My final question which somebody suggested to use CurveFitting for I am a little stumped on. I think the main reason is I am not sure what it is the question is asking me to do to begin with. I am going to quote it so that all is clear, then I will explain what I have figured out so far.
Approximate the derivative of the interpolated function for the following data, using Central Difference method at x=2.5 and using h=0.01
x | Y
2 | -7
3 | 3.2
4 | 4.1
Hint: You need to interpolate the data because the data point is not in the chart.
Well I found a couple ways to interpolate the data (This is assuming I am supposed to be interpolating the data to find the correspoding number for an x of 2.5):
> PolynomialInterpolation([[2,-7],[3,3.2],[4,4.1],[5,10.45]], (2.5));
Firstly, these are different answers... and neither matches the final answer for the problem. So If either of these numbers are correct its only part of what I am supposed to be accomplishing