Arduino 三角函数
你需要使用三角几何来计算移动物体的距离或角速度。Arduino提供了传统的三角函数（sin，cos，tan，asin，acos，atan），可以通过编写它们的原型来概括。Math.h包含三角函数的原型。
三角函数的精确语法
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
例子
double sine = sin(2); // approximately 0.90929737091 double cosine = cos(2); // approximately -0.41614685058 double tangent = tan(2); // approximately -2.18503975868
