Functions and near-numbers (part 1!)

The first 4:15 of the video on functions and near-numbers is online! It goes through all of the basics, as well as some examples of reciprocation; the full video will include several more function examples, and it should be online in a few weeks.

The learning goals are:

• to be able to use graphs of functions to apply those functions to near-numbers, remembering that what matters is what happens when the near-numbers keep squeezing, and
• to remember that functions undefined at some point (such as when we try to divide by zero by plugging 0 into the reciprocation function x ↦1/x) are still undefined and that we mark near-number results by an asterisk (*) when input values are lost due to the function being undefined.

Note that this video shows the answers to 1/+∞, 1/–∞, and all of those shown in the video's thumbnail!