( y By using the method of least squares, find the best parabola through the points. (1,-1). (0,-2). (-1,1). (2,3) Step 1. The general equation of a para ola is co + Cz + Czz = y Plugging the data points into this formula gives a matrix equation Ac-y Step 2. The matibx equation Ae y has no solution, so instead we use the normal equation ATAe = ATy ATA- ATy Step 3. Solving the normal equation gives the answer which corresponds to the formula