It was four years ago when I discovered Khan Academy, which as far as I can remember a Youtube channel with more than a thousand videos. If I am not mistaken, it was only then managed by Salman Khan, it’s founder. A year ago or two, when I searched the internet, I learned that Khan Academy has […]

Continue reading…

# Audio, Video and Animation

## Understanding the Concept of Inverse Functions

Let us consider the functions and . The table on the left shows the ordered pairs . We used and substitute them to in the second table. As we can see, all the values of are the same as those of in the first table. For example, if we have in the first table, applying , we […]

Continue reading…

## How to Use the Factorial Notation

We have had several discussions about the factorial notation, so I think this introduction is a bit late. However, it is important that you know these basic facts in order to perform calculations and understand better in later discussions. The factorial of a non-negative integer is the product of all the positive numbers less than . For […]

Continue reading…