25.4.5 Graph and Properties of the Tangent Function
Core ideatan looks like a series of curves shooting upward, repeating every π and breaking off at certain angles where it races toward infinity.
Module goal. We 'unroll' the turning of a point on the unit circle into a wavy curve, getting a firm grip on period, even/odd symmetry, increasing/decreasing behavior, and extremes, to lay the groundwork for parameter transformations and the laws of sines and cosines.