how would i create a function in C that accepts one input number

and returns a double number. The themes for the functions should be one of the following:  Calculates 3.14 times of the square of input number. For example, if 2 is input then 12.56 should be returned. (e.g. 3.14*2*2 = 12.56)  Divides the number by 3 and returns the result. For example, if 6 was input then 2.0 should be returned.  Squares the number and returns the result. For example, if 12.1 was entered then 146.41 would be returned. You should provide both your C code and an example call to the C code function. while providing an overview of what your function is doing. . Include header documentation in the code as well as internal code documentation. Provide a screen capture showing the results of testing your code in an online compiler. Be sure to test your code with several test cases and show your test case table.