The mathematica function for the exponential is Exp[]. 1.1. Evaluating E^x//FullForm should show you that the head of this expression is not Exp but Power 1.2. Defining the exponential function in a similar fashion like you did, would require something like (E^#)& (probably, I haven't tested it)
The problem you are having with Log[] is because the logarithm is not defined for negative input values while your spxey[[1]]==-1
hope that helps
Thanks! Exp works! but unfortunately, Log doesn't work, though I edited spxey = {0.75, 2.5, 4.25, 6}; and data = Table[{x, f[x]}, {x, 1, 6, 0.1}]; Can You help me?
spxey = {0.75, 2.5, 4.25, 6};
data = Table[{x, f[x]}, {x, 1, 6, 0.1}];
What exactly is wrong because I can't see any prob. It evaluates just fine for me.
Perhaps you could explain what you were expecting to receive as output and what you actually get?
