Cos(x) and sin(x)
They return the trigonometric value of the cosine and sine of x radians respectively. If you don't know what radians are, i suggest going to the wolfram site, or just google.

cos(4*5)
= cos(20 radians)
if you want cos(20 degrees)
just do something like:
[Highlight=VB]
Pubilc Function DegCos(Byval x as double)
Dim Rad_to_Deg as double
Rad_to_Deg = 3.14159/180
DegCos= cos(x * Rad_to_Deg)
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based on the fact that 180 degrees = Pi radians, so Degcos(180) = cos(180*pi/180) = cos(pi) in radians = cos(180) in degrees