I noticed that a lot of students have problems with H2 maths
Vectors, with all the finding of shortest distance between line and
plane, between point and line, etc. So I'm going to share with you
what I think is the right way to study, prepare and understand the
topic of vectors.
The thing is, there is no need to memorise all the formulae!
They will kill you if you use and apply it blindly. You are more
likely to careless, especially when trigo is involved. You might
get the angle wrongly, etc etc. And so many formulae will make you
go bonkers; you still have other topics (and subjects) to take care
of. What AB dot unit vector n, AB cross unit vector n, etc... will
decimate you in no time when you have to handle all the
subjects.
The key thing, as my students would know, is to make full use of
your power and concept of trigonometry (O levels sufficient) as
well as the basic and fundamental things you learned about vectors.
I myself cannot remember any formulae off-hand for finding shortest
distance, but from trigo concept, I can always come up with the
equation in about 2 to 3 steps. Not much extra to use in exams,
considering that you save a lot of brain capacity for other
topics.
How do go about doing
this?
Look through your notes again. Your teachers should have given
you notes on how to arrive at the shortest distance equations by
derivation. Try to understand how they come about, and with that
understanding, do your tutorials and practices with it. Then you
will still most likely be able to do A levels vectors question many
years after you finish A levels with basic O level trigo.