The Gordian knot

Well St. Patrick's day is fun. Structures CW is the order of the day today, it's written but not finished until this maths works which at present it won't..... Nearly 3 hours of trying and failing this far today. The most irritating thing is I had used an equation which had worked perfectly, then many weeks after issuing the CW the lecture says we have to use a particular method, so I'm back to square one from what was a finished piece if work!!!!

At least yesterday was fun :)

PS, i won in the end, I think.......