The C++ programming language contains several built-in functions to perform simple as well as complex calculations and data manipulations in user programs. The collection of these library functions in C++ is termed a Standard Library. Library functions in C++ are declared and defined in special files called “Header Files” which we can reference in our C++ programs using the “include” directive.
example
sqrt(x)
pow(base,exponent)
exp(x)
tan(x)
etc..
