Before we get into the details, let's understand the basics. What is a function in mathematics? A function represents the relation between input and output. We generally use 
to denote a function. For instance, 
implies a function that takes 
as an input and returns 
as an output. It can also be represented as 
.
Here, we have a function, 
, and we can plot and see what our function looks like:
The smallest value of a function is called the minimum of a function. As you can see in the preceding plot, the minimum of the 
function lies at 0. The previous function is called a convex function, and is where we have only one minimum value. A function is called a non-convex function when there is more than one minimum value. As we can see in the following diagram, a non-convex function can have many local minima and one global minimum value, whereas...