Section: Mathematical Functions
tan function for its argument.  The general
syntax for its use is
y = tan(x)
where x is an n-dimensional array of numerical type.
Integer types are promoted to the double type prior to
calculation of the tan function.  Output y is of the
same size and type as the input x, (unless x is an
integer, in which case y is a double type).  
tan function is defined for all real
valued arguments x by the infinite summation
 
or alternately by the ratio
 
For complex valued arguments z, the tangent is computed via
 
tan(x)
function over the interval [-1,1]:
--> t = linspace(-1,1); --> plot(t,tan(t))
