October 2005
Intermediate to advanced
372 pages
11h 35m
English
acos()
float acos ( float num )The acos() function calculates the arc cosine value of the number provided as its only parameter, essentially reversing the operation of cos(). The return value is in radians—you should use the rad2deg() to convert radians to degrees.
$acos1 = acos(0.4346);
$acos2 = acos(cos(80));