Function atan 

pub fn atan(y: number, x: option<number>) -> number

Returns the arc tangent of y/x, in radians.

Parameters

• y: a number.
• x: a number (default 1).

Return value

The arc tangent of y/x, in radians, as a float. The signs of both arguments are used to find the quadrant of the result, and the function handles the case of x being zero correctly.

Examples

print(math.atan(1))        --> 0.7853981633974483  (π/4)
print(math.atan(1, 0))     --> 1.5707963267948966  (π/2)
print(math.atan(-1, -1))   --> -2.35619449019234545  (third quadrant)

See also

acos, asin, tan