What is the role of loss function in machine learning algorithms? Explain any two commonly used loss functions in machine learning algorithms.

Supervised Learning,
Unsupervised learning,

Consider the following table for the connections between the input neurons and the hidden layer neurons

 If the input vectors are  and initial values of three weight vectors are , then calculate the resulting weight found after training the competitive layer with Kohonen's rule and a learning rate  of 0.5 on the input-series in order I₁, I₂ and I₃.