It might sound laborious ..but it’s not a big deal. As the name implies it is a function but what is the term **“cost” ? **Cost simply means **error or lost**. So lets get into the more deeper side of cost function.

For the sake of understanding better I’m going to explain cost function in terms of simple linear regression. For those who don’t have a basic understanding of simple linear regression check out previous post https://arjun-s.medium.com/simple-linear-regression-ground-level-understanding-e278ebf028d3.

Before starting let me give you a quick recap on hypothesis.

The hypothesis of a simple linear regression model is given below.