added some math functions such as sin, cos, asin, atan, etc.
Only tested on konsole with default settings
https://user-images.githubusercontent.com/71960289/98656187-4e13e700-2338-11eb-9b73-4f647f2f3775.png
https://user-images.githubusercontent.com/71960289/98656841-0fcaf780-2339-11eb-9713-d9164653fd75.png