TITLE(Trig @@ Trigonometric Functions)
USAGE(
cos(x)
sin(x)
tan(x)
acos(x)
asin(x)
atan(x)
atan2(y, x)
)
ALIAS(cos)
ALIAS(sin)
ALIAS(tan)
ALIAS(acos)
ALIAS(asin)
ALIAS(atan)
ALIAS(atan2)
DESCRIPTION(
These functions give the obvious trigonometric functions.  They
respectively compute the cosine, sine, tangent, arc-cosine, arc-sine,
arc-tangent and arc-tangent of two arguments.
)
SEEALSO(
LANG(LINK(Log)), LANG(LINK(Math)).
)
EXAMPLES(
x <- 1:99/100
all(Mod(1 - (cos(x) + 1i*sin(x)) / exp(1i*x)) < 1.1 * .Machine$double.eps)
 2* abs(1 - x / acos(cos(x))) / .Machine$double.eps #-- depends ?
all(abs(1 - x / asin(sin(x))) <= .Machine$double.eps) # TRUE (Solaris)
all(abs(1 - x / atan(tan(x))) <= .Machine$double.eps) # TRUE (Solaris)
)

