📗 [3 points] (new) There are three training documents in a training set with words in each document. The word "" appeared in total in the three documents. The TF-IDF features for the word "" for the first two documents are both \(0\). What is the TF-IDF feature for the third document? Note: there are two possible answers to this question, one of them is \(0\), what is the other one?

📗 Answer: . Calculate

📗 [3 points] (new) Suppose there are two classes \(C\) for "cats" and \(F\) for "flerkens" and \(4\) training items each with a single numerical feature \(\left(x_{i}, y_{i}\right)\) = . What is the minimum and maximum (due to the different ways the training set is divided into folds) 2-fold cross validation accuracy of the 1-nearest neighbor classifier on this training set? Enter two numbers between 0 and 1. If the minimum and the maximum are the same, enter the same number twice.

📗 Answer (comma separated vector): . Calculate

📗 [3 points] (new) When training a recurrent neural network with input features, hidden recurrent units, and output units. During one step of stochastic gradient descent, for one training item sequence of length , the values of weights and biases are updated (a weight is considered updated if one gradient descent step is applied, including when the gradient is 0). For another training item sequence of length , how many weights and biases are updated? Enter a single integer: the total number of weights plus biases.

📗 Answer: . Calculate

📗 [3 points] (new) When training policy networks to control Flappy Birds, genetic algorithm is used and the fitness of the birds in the population are . During the cross-over phase, reproduction probabilities are computed based on fitness and sampling is done with replacement. What is the probability that the first bird (i.e. with fitness ) is sampled twice in a single iteration (single cross-over between two birds) of cross-over (thus surviving to the next generation)?

📗 Answer: . Calculate