You need to use Trigonometry practically like calculating the distance for moving object or angular speed. Arduino provides traditional trigonometric functions (sin, cos, tan, asin, acos, atan) that can be summarized by writing their prototypes. Math.h contains the trigonometry function's prototype.
Trigonometric Exact Syntax
double sin(double x); //returns sine of x radians double cos(double y); //returns cosine of y radians double tan(double x); //returns the tangent of x radians double acos(double x); //returns A, the angle corresponding to cos (A) = x double asin(double x); //returns A, the angle corresponding to sin (A) = x double atan(double x); //returns A, the angle corresponding to tan (A) = x
Example
double sine = sin(2); // approximately 0.90929737091 double cosine = cos(2); // approximately -0.41614685058 double tangent = tan(2); // approximately -2.18503975868