A few questions regarding setting out work in exams (1 Viewer)

[MrGresh]

Ok, so just a few little things I thought I'd ask...

(1) cis stuff
is it ok to write cis(n) in exams or is it best practice to fully write out cos(n) + i sin(n)?

(2) vector stuff
is it ok to use whatever vector form we want in writing (i.e. column, component etc) and then convert back to the one given in the question for our final answer. I hate component form with a burning passion

Thanks!

 

[erucibon]

1) I have been told you should stick to cosn + isinn but they probably won't mark you down for cis
2) yes

 

[MrGresh]

1) I have been told you should stick to cosn + isinn but they probably won't mark you down for cis
2) yes

Ok, thanks!

 

[Trebla]

Ok, so just a few little things I thought I'd ask...

(1) cis stuff
is it ok to write cis(n) in exams or is it best practice to fully write out cos(n) + i sin(n)?

(2) vector stuff
is it ok to use whatever vector form we want in writing (i.e. column, component etc) and then convert back to the one given in the question for our final answer. I hate component form with a burning passion

Thanks!

Both yes. You can also write e^ix if your aim is just to abbreviate.

 

[MrGresh]

Both yes. You can also write e^ix if your aim is just to abbreviate.

o true dat, thanks!

 

[beetree1]

i dont understand why anyone would come up with component form it makes me so angry

 

[MrGresh]

i dont understand why anyone would come up with component form it makes me so angry

Ikr! All the papers use it and its so friggin hard to read...

Like column form is <3

 

[Trebla]

i dont understand why anyone would come up with component form it makes me so angry

Ikr! All the papers use it and its so friggin hard to read...

Like column form is <3

Fun fact, in some university level textbooks, the i, j, k are actually in bold rather than have a squiggly line underneath them. This makes it easy to read.

That being said, once you start going into proper linear algebra with vectors and matrices into n dimensions, the i, j, k notation is effectively abandoned altogether. I think it is still used in engineering contexts though...