Limits from graphs of functions

Answers appear on the plot as black dots. After pushing 'show answers' button, every wrong answer is replaced with the correct one, and red dots appear in correct places. In addition, any limit that was correct turns green, incorrect turns red. You can use DNE as answer, which plots a vertical line to indicate the limit does not exist. Note that functions are random, but answers are always integers. \(\require{color}\)