Q1. What is the effect of correlation between two features on the feature space representation?

Q2. Is it possible that the addition of a new feature decrease the accuracy of the NN classifier? How?

Q3. Is it correct that for nearest neighbor classifier, it is always best to have all features scaled to the same range? Show why or give a counter example.

Q4. Can the nearest neighbor classifier be applied to feature vectors of different length? Is it possible to do so if you have a function that takes in two feature vectors (possibly of different lengths), and outputs the similarity/distance between them? Suggest a possible function of this nature, and a classification problem, where it can be applied.