. A second-order response surface model in two variables is y= 69.0+1.6x| +1.1x2 -1x]

-1.2.x +0.3x *2

(a) Generate a two-dimensional contour plot for this model over the region 4-25x) ≤+2, 1=1,2, and select the values of x1 and X2 that maximize y.

(b) Find the two equations given by 29 =0 and 2x1 Show that the solution to these equations for the optimum condi-

tions x1 and X2 are the same as those found graphically in part (a).