MATH U101 · Narrated walkthrough · Tutorial 5 · Module 3 §14.2
Finding multivariable limits: four tools
A short narrated lesson on Tutorial 5 questions 1, 6, 7, 8 and 9: why limits in two variables are harder, and four tools that handle every path at once. Press play, keep the sound on, and answer the four questions it stops to ask you.
About seven minutes, watch once. The narration stops four times to ask what the next move is. Commit to an answer before it continues: those pauses are the point, because they practise starting a question, not following one. Captions are on by default; the full transcript is below the player.
Redo one of these on paper without looking, then check against the written solutions on the tutorial companion. The other half of Tutorial 5 (showing a limit does not exist, and where functions are continuous) is in the sibling walkthrough, limits: the two-path test. The rules themselves are in the Module 3 notes and the Module 3 lesson.