Imagine you train your three different functions using polynomial regression. The first function f1 is learned using p=1. The second function f2 is learned using p=2. The third function f4 is learned using p=4. You plot the training and test performance, under these increasing p, and get the following plot. Part (a) [10 MarKs] Assume we have one-dimensional inputs xR. Write down the function f4. For this answer, write the feature vector that is used for f4 and explicitly state how many weights are learned for f4, which has degree p=4. Part (b) [15 Marks] Based on this plot, what model might you deploy? Explain your