Sinus and Coitus

Sinus and Coitus are two very important functions in mathematics. The derivative (which gives the slope of a function at the point) of sinus is coitus. And the derivative of coitus is coitus interruptus, because you need to interrupt the function to measure its slope. Usually people will look at you really weird when you use those terms, because they are not used such high mathematics.

Person 1: Mathematics homeworks was really hard last night. The sinus and coitus excercises were kind of tricky, but coitus interruptus? Nah man. I went to sleep early and decided to finish coitus interruptus later
Person 2: wtf?