## well, did we, okay did we determine that Moebius maps were like isometries or whatever?

From the Michigan Corpus of Academic Spoken English, a 16,000 word transcript of an undergraduate math study session.  In case you ever wanted to know what it really sounds like when students work on our homework.

S1: what if- what if A plus B, equals two times Y and C plus D equals two? [S3: yeah. ] it just has to be proportional so you can’t break it up… but if we have A and C being whatever, then let’s make them something that works.

S2: like one?

S1: let’s… like what if you made, A equal Z and C equal one or something.

S2: but they can’t equal whatever because in the bottom A over C has to equal Z.

S1: i know. [S2: okay ] you make it so that it works.

S2: so you want A to be equal to Z, and C to be equal to one.

S1: okay, so what if we do that…? well no then that gives us uh, Z in the Y equation. unless B equals like Y minus Z or something well it could be done… it’s gonna get complicated though… so if A equals Z,

S2: i think this sucks.