For the purposes of PROMOTIC system, it is more usefull to use the method: Pm.Cos.
n = Cos(number)
|number||(Double) Angle in radians. The degrees can be transferred into radians by multiplying the input value by 0.017453293 (=2*Pi/360).|
Dim nAngle, nSecant
nAngle = 1.3 'define angle in radians
nSecant = 1/Cos(nAngle) 'calculate secant