  Drones have gained popularity in a wide range of field ranging from aerial
photography, aerial mapping, and investigation of electric power lines. Every
drone that we know today is carrying out some kind of control algorithm at the
low level in order to manoeuvre itself around. For the quadrotor to either
control itself autonomously or to develop a high-level user interface for us to
control it, we need to understand the basic mathematics behind how it
functions. This paper aims to explain the mathematical modelling of the
dynamics of a 3 Dimensional quadrotor. As it may seem like a trivial task, it
plays a vital role in how we control the drone. Also, additional effort has
been taken to explain the transformations of the drone's frame of reference to
the inertial frame of reference.
