(a) Machine learning is being increasingly used in many applications. i. When should machine learning be used? ii. Discuss the two stages of supervised learning. iii. What is the goal of unsupervised learning?[3 ma) Consider the regression problem with the following training set containing (b) Consider the regression problem with the following training set containing 5 examples and apply -nearest neighbours (NN) algorithm with Euclide an distance.

i. Predict the label of the test object (–1, 1) for k = 2. ii. What is the prediction for the test object (−1,1) for k = 3? iii. What are the advantages of ANN? (c) Briefly discuss two approaches to directly estimating the test error associ-ated with fitting a particular machine learning method on a set of observa-tions.[6 marks] (d) Briefly explain generalised additive models (GAMs). What are the advantages and disadvantages of the GAMS?[6 marks]