The atan2() function in C++ returns the inverse tangent of a coordinate in radians. It is defined in the cmath header file.
Mathematically, atan2(y, x) = tan-1(y/x).
Example
atan2() Syntax
The syntax of the atan2() function is:
atan2(double y, double x);
atan2() Parameters
The atan2() function takes the following parameters:
- x - floating-point number that represents the proportion of the x-coordinate
- y - floating-point number that represents the proportion of the y-coordinate
atan2() Return Value
The atan2() function returns:
- a floating-point value in the range of [-π, π].
- 0 if both x and y are zero
atan2() Prototypes
The prototypes of atan2() as defined in the cmath header file are:
double atan2(double y, double x);
float atan2(float y, float x);
long double atan2(long double y, long double x);
// for combinations of arithmetic types
double atan2(Type1 y, Type2 x);
Example 1: C++ atan2()
Output
atan2(y/x) = -0.785398 radians atan2(y/x) = -45 degrees
Example 2: C++ atan2() with Different Types
In this program, we will use arguments of different data types with the atan2() function.
Output
atan2(y/x) = 3.04694 radians atan2(y/x) = 174.577 degrees