Tangent Curve

The applet below has 4 different transformations of the curve, y=tan x. Move the sliders for a,b,c, and d, and see how the graph changes. Note: x is in radians. You can also show the asymptotes, by pushing the check box. Play around until you understand the idea, and then answer the questions below.
Question 1: Consider the general tangent function, y=a tan(b(x-c))+d. What is the principal axis and the period? Question 2: Does this curve appear to have an amplitude? Question 3: What must tan (x-pi) simplify to?