Hun-dun-dun da da dun-da

Wrote up from 9.30 pm until 2.30 am. Corrected errors along the way in almost every Lagrange question. Finished up to the end of question 7, inventing a new notation for matrix derivatives in the process [I probably say this every week, but: I do wonder how Chris intended for us to do that question]. This morning I sat down to write up question 8 with its two measley solutions. After two hours of correcting errors, question 8 no longer had any solutions at all.

I don't care about the bleeding solutions. I'm not playing any more. I'm handing in at the end of the lecture and to hell with courage and persistence.

Question 9 was as easy as expected, though.