Functions Defined In Module

The functions defined have domain R

Which of the functions defined below is one one function ?

Show that the function defined by f(x)=cos(x^(2)) is a continuous function.

Types OF Function || Defination OF Function

If f be the greatest integer function and g be the moduls function, then (gof) (-(5)/(2)) - (fog ) (-(5)/(3))=

Is the function defined by f(x)=|x|