No predefined 'header' function in the standard C libraries. There are header files, if that's what you mean.
Platform dependent, possibly LIBC.LIB or something like that.
list of header files in c and function prototype associated with each file
Include the header file math.h and use the function acos(d)
int86 is a function in TurboC, header dos.h, consult the built-in help.
Constants, typedefs, function prototypes. If you want to know more, load it into a text editor.
to include the header files.
There are no 'sections' in C source, you can define functions anywhere, except inside another function or variable/type definition.
You need to #include the header file that contains the missing function's declaration.
it is sqrt in header math.h
Header File in C/C++ are the files which contains the definition of the pre-defined functions, data-types & constants, etc. By adding the header file you reduce your job of defining the same functions which are defined earlier by someone else & you can use those functions/data-types easily.
It's 1405 in my Linux box.
COUT is an inbuilt function in c++ language. Cout is used to print something on to the standard output.