acos, asin, atan, atan2

acos, asin, atan, atan2 — perform trigonometric arc functions.

Syntax

acos (number)
asin (number)
atan (number)
atan2 (number, number)

		

Arguments

number

Any integer or real number. Non-numbers are treated as zero.

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