# Study Update: MST121, MS221 and M255 End, M263 Begins

It's now a year since I started studying again, part-time, towards a BSc. I last updated the public about six months ago, so here's the latest for those very few readers that may be interested!

# Further Adventures as a Student: MST121, MS221 and M255

Back in September of last year, I started studying part-time, for a BSc in Maths, with some computing thrown in. It's now six months since I made that first post, and this is a really, really busy phase of the degree course, so I thought it might be time for an update.

# A Second Cheat Sheet: the Sine Rule and the Cosine Rule

More adventures in MST121: Using Mathematics. *B3: Modelling with Vectors* took an unexpected turn into matters of triangle geometry - and not the more beginner-friendly right-angled variety either - which left me getting to grips with the Sine Rule and the Cosine Rule.

Much like my experiences with Sigma Notation, the principles are straightforward, but I kept failing to spot which equations to apply.

So I've knocked up a further cheat sheet. Here are the files:

# Sigma Notation Cheat Sheet

I'm just over a quarter of the way through MST121: Using Mathematics, which I started back in September. My impression is that it's starting to get tougher, but it may just be that my mind has been elsewhere.

One concept with which I found myself to be less confident is Sigma Notation. The principle itself is fairly straightforward (it's kind of like a `for`

loop, if you ask me) but getting actual numbers out of the other side was another matter.

The problem was that I was consistently failing to spot the patterns that indicate that you can substitute in other, hopefully simpler, expressions. So I made a little *aide memoire* to print out. It covers the ~~three~~ four initial, erm, refactorings that have cropped up, and I figured I may as well share it.