I came across this question on coursera's machine learning course. Could anyone explain me how do you solve the following questions?
According to my understanding(maybe I am wrong), theta is always orthogonal to the decision boundary. By looking at the data it seems that decision boundary should be Y-axis. As Y-axis will separate the positive and negatives. Moreover, it will have the maximum margin.
But I don't understand how to calculate norm of theta. As the theta vector is unknown.
Note: This is not a homework question. I already know the correct answer to the question. But I don't know how to solve this question. I just want to know how to solve this question.