Assignment:
Consider the graph of y = tan x.
(a) How does it show that the tangent of 90 degrees is undefined?
(b) What are other undefined x values?
(c) What is the value of the tangent of angles that are close to 90 degrees (say 89.9 degrees and 90.01 degrees)?
(d) How does the graph show this?
![634_tangent.JPG](https://secure.tutorsglobe.com/CMSImages/634_tangent.JPG)
Provide complete and step by step solution for the question and show calculations and use formulas.