Submitted by Anonymous (not verified) on
Forums:
One of the main things that worries me about STEP is that in a lot of questions I end up hitting a road block because I need to use a piece of maths I've never come across before. For example, I did a question yesterday and to make any progress into part 2 I needed to know that arctan(1/x)=pi/2 - arctan(x). This just seems so obscure and I had never seen it before, yet it stopped me in my tracks so I could only get 8/20 on a question. Obviously I know it now, but there seems to be something like this in a lot of questions I try.
Is there anywhere I could get a list of all these sort of little facts we're meant to know?
Any advice?
I don't want to be throwing marks away because of something silly that would have taken me all of 30 second to learn!
Thanks!
Obscure Facts
Submitted by stcs on
I have a couple of comments about that (well, three).
1) It is a mistake to think in terms of learnt facts. There are far too many facts of this sort to learn one by one; you need to identify the sort of thing it might be and work it out from there.
2) The formula you refer to is just a combination of things you already know: $\cot x= 1/\tan x$ and
$\tan(\pi/2 -x) = \cot x$. It is disguised by the inverse trig functions, but is the sort of thing you need to be on the look-out for,
3) I don't remember the exact question, but in general it is unlikely that not knowing or being able to work out a particular result would prevent you from completing the rest of the question. Often, you have to write `I'll come back to this' and continue with the question.
Stephen