## C standard mathematical functions and Arduino

As we have already seen, almost all standard C and C++ entities supported by the compiler
**avr-g++** should work with Arduino. This is also true for C mathematical functions.

This group of functions is a part of the (famous) C standard library. A lot of functions of this group are inherited in C++. There are some differences between C and C++ in the use of complex numbers. C++ doesn't provide complex numbers handling from that library but from its own C++ standard library by using the class template `std::complex`

.

Almost all these functions are designed to work with and manipulate floating-point numbers. In standard C, this library is known as `math.h`

(a filename), which we mention in the header of a C program, so that we can use its functions.

### Trigonometric C functions in the Arduino core

We often need to make some trigonometric calculations, from determining distances an object has moved, to angular speed, and many other real-world properties. Sometimes...