To make a trend analysis of six evenly spaced data points, one can use orthogonal polynomials with respect to evaluation at the points t = 5, 3, 1, 1, 3, and 5.
a. Show that the first three orthogonal polynomials are
(The polynomial p2 has been scaled so that its values at the evaluation points are small integers.)
b. Fit a quadratic trend function to the data
