3.2.1 Zero-points


All zero-points of the selected function will be detected. In addition to
the x-value you will also get the following information about the type of
the zero-point:

  -+     (crossing x-axis from - to +)
  +-     (crossing x-axis from + to -)
  ++/--  (Touching x-axis from the positive/negative sector).

All other discussion-parts are based on the zero-point detection.