3. (8 points)
Support vector machine: Given a set of binary data in format of ($x_1$, $x_2$, class), if
we already found the three support vectors being: (1, 1, -1), (2, 0, -1), and (2, 2,
+1) as shown in the following graph:
3
2
1
0
0
1
2
3
(a) Find the decision boundary (represent it using linear equation) and its
geometric margin.
(b) Given a new data at (2.5, 1), predict its class using the result found in (a)