Exercise Solution 2.2
Formula [2.26] provides a quadratic polynomial approximation p2(x) for the function f(x):
[2.26]
We have
[s1]
and
[s2]
Valuing f, 
f, and 2f at x[0] = (0, 0), we obtain
[s3]
[s4]
[s5]
Substituting these into [2.26], our result is
[s6]
[s7]
