COS function

Purpose

Return the cosine of an angle.

Syntax

y = COS(numeric_expression)

Remarks

numeric_expression is an angle specified in radians.  To convert radians to degrees, multiply by 57.29577951308232##.  To convert degrees to radians, multiply by 0.0174532925199433##.  For more information on radians, see the ATN function.

COS returns an Extended-precision value that always ranges between -1 and +1 inclusive.

The Inverse Cosine (ARCCOS) of a value can be calculated as follows:

pi# = 3.141592653589793##

ArcCos = pi# / 2 - ATN(Value / SQR(1 - Value * Value))

The Hyperbolic Cosine (COSH) of a value can also be calculated:

CosH = (EXP(Value) + EXP(-Value)) / 2

The Inverse Hyperbolic Cosine (ARCCOSH) of a value can also be calculated:

ArcCosH = LOG(Value + SQR(Value * Value - 1))

 

' Useful Macro functions

MACRO Pi = 3.141592653589793##

MACRO DegreesToRadians(dpDegrees) = (dpDegrees*0.0174532925199433##)

MACRO RadiansToDegrees(dpRadians) = (dpRadians*57.29577951308232##)

See also

ATN, SIN, TAN

Example

pi## = 3.141592653589793##

' we could also use pi## = ATN(1) * 4

FOR I& = 0 TO 360 STEP 45

  x$ = "Cosine of " + FORMAT$(I&, "* 0") + _

    " degrees = " + FORMAT$(COS(pi## / 180 * _

    I&), "* 0.00")

NEXT I&

Result

Cosine of   0 degrees =  1.00

Cosine of  45 degrees =  0.71

Cosine of  90 degrees =  0.00

Cosine of 135 degrees = -0.71

Cosine of 180 degrees = -1.00

Cosine of 225 degrees = -0.71

Cosine of 270 degrees =  0.00

Cosine of 315 degrees =  0.71

Cosine of 360 degrees =  1.00