🚀 go-pugleaf

Dividing by zero is not defined.  It is not pssible to compare dividing by a real number and
divind by zero.  If you look at the definition of functional spaces, for instance, multiplying
by zero itself is defined  as a separate operation.  Although tan (90) may not be defined
in this sense, cotangen (90) = 0.  Tangent-type functions (including) Cotangent are functions
with infinite discontinuties.  One way to see why tan (90) can't really be said to be
infinity is can be seen from the following example.

	Tan (0) = 0
	Tan (pi/4) = 1.
	Tan (90)_ = ?
	Tan  (90 + theta) = - cotangent (theta)

Thus to the right of pi/2 (in the period 0 - 2*pi), the tangent function starts from - (negative) Large
values.  Thus at pi/2, it is not exactly defined, since it could be +inf (approaching it from
left) or -inf (approaching it from right). Hope that this answers some of your questions.
	
S.Shankar
Tech CAD
INTEL