acos, asin, atan, atan2

Arguments

Returns

The result of the arc trigonometric function in radians.

Description

These functions perform the arc trigonometric functions arc cosine, arc sine, arc tangent, and arc tangent with 2 arguments. The atan2 function is equivalent to:

atan( y / x );

except that atan2 is able to correctly handle x and y values of zero.

Example

Gamma> acos (0.5);
1.0471975511965978534
Gamma> asin (0.5);
0.52359877559829892668
Gamma> atan (2);
1.107148717794090409
Gamma> atan2 (1, 2);
0.46364760900080609352
Gamma> atan2 (1, 0);
1.570796326794896558
Gamma> atan2 (0, 2);
0
Gamma>  
		

See Also

sin, cos, tan