whatever you do, DO NOT TOUCH THE RED BUTTON!!!
seriously dont drop it, i was in the same position as you last year, and belive me maths ext is so important in getting you good marks in 2unit as well as saving ur UAI.
Eg. i did ext maths and kept failing in class but most of the work done in Ext1 maths is also covered in 2 unit, so you study once for the ext maths exam, you fail, but then when u study the same thing again for the 2 unit assesment some time later, you already know half the stuff and the exam is relatively easy in comparison, hence you get the distinct advantige over the people not doing ext maths.
I never took ext math seriously but being hit with those 'harder' questions made me think of 2 unit as easy stuff, and when HSC came we all got the that nasty exam (it was in the news) and the people in my school not doing 3 unit were totally lost. i myself pulled a 86% in that exam and damn lucky, but if i didnt do ext maths it would be ~70%.
finally i was doing 12 units and never thought maths ext was going to count, but i did it anyway (someone told me i had to sit for the exam) and failed badly, i estimated my mark to be ~30% if im lucky, the actual results in mail said i got 66% (very nicely scaled
), and not only that, it counted in my uai calculation over physics in which i got 77%. so Maths Ext 66% > Physics 77%.
So as you see there is no point in dropping it this early, with maths ext you will improve your 2 unit mark, and when you get to uni, should you pick an engineering degree you will wonder why in the hell you didnt take 4 unit maths, cause 2 topics from it were already covered in the first month of uni.
Its doable!!!