Evaluate the derivative using the definition of derivative limit notation

The video tutorial discusses the concept of derivatives, focusing on the limit definition. The instructor explains how to identify the function to differentiate and simplifies the problem by removing unnecessary complexities. The tutorial concludes with calculating the derivative of a simple function, emphasizing the process and understanding of derivatives in calculus.

What is the derivative of the function X^2 - 4 as stated in the text?

How does the teacher simplify the process of finding the derivative?