Consider the XOR problem where there are four training points: (1, 1, −),(1, 0, +),(0, 1, +),(0, 0, −). Transform the data into the following feature space:
Φ = (1, √ 2x1, √ 2x2, √ 2x1x2, x2 1, x2 2).
Find the maximum margin linear decision boundary in the transformed space.