# First Year Mathematics A (Differentiation & Linear Algebra) (1 Viewer)

#### Flop21

##### Well-Known Member
Is there a thread for math help for 1131 (or other first year math equivalent) on here?

If not, this thread will be for posting (uni math) questions to get help for.

#### Flop21

##### Well-Known Member

I'm watching Kahn academy videos on vectors. I'm understanding everything so far, the guy is using (x,y) notation, but then suddenly switches to a different notation I'm not familiar with. This happened in my class lecture as well.

Can someone help me understand what this notation means:

#### Flop21

##### Well-Known Member

How is R^2 different to R? (and by R I mean the special R/real numbers).

#### Flop21

##### Well-Known Member

Good idea - perhaps this thread should be moved to the UNSW science faculty sub forum though?

http://community.boredofstudies.org/139/faculties-science-medicine/
Yeah wasn't sure whether to or not. I'm not sure how 1st year uni maths differs from uni to uni, but assumed it would be similar. So everyone can just post their math problems and get help here [or mods can move it wherever best].

#### InteGrand

##### Well-Known Member

How is R^2 different to R? (and by R I mean the special R/real numbers).
$\bg_white \noindent \mathbb{R} refers to the set of all real numbers (think real number line). \mathbb{R}^2 refers to the set of all ordered pairs of real numbers (think of the Cartesian plane).$

#### InteGrand

##### Well-Known Member

I'm watching Kahn academy videos on vectors. I'm understanding everything so far, the guy is using (x,y) notation, but then suddenly switches to a different notation I'm not familiar with. This happened in my class lecture as well.

Can someone help me understand what this notation means:
$\bg_white \noindent That's just another notation for vectors. The top number refers to the first component, and the bottom number refers to the second component.$

##### Cult of Personality

the unsw mathematics society has a facebook page for such queries

Did you join MathSoc?

#### leehuan

##### Well-Known Member

I've just been using my own thread for assistance with 1151.

#### dan964

##### MOD
Moderator

I'm watching Kahn academy videos on vectors. I'm understanding everything so far, the guy is using (x,y) notation, but then suddenly switches to a different notation I'm not familiar with. This happened in my class lecture as well.

Can someone help me understand what this notation means:
That notation with a vertical arrow is used to refer to a vector. Typically, e.g. in MATH201 at UOW, this notation is used to refer to row vectors; although it can be used to refer to column vectors as in the case here.

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#### Silly Sausage

##### Well-Known Member

That notation with a vertical arrow is used to refer to a vector. Typically, e.g. in MATH201 at UOW, this notation is used to refer to row vectors; although it can be used to refer to column vectors as in the case here.

Some of the math tutors\lecturers at USYD refer to the arrow notation as the "Russian way" of writing it. Apparently the normal westernised one is basically a squiggly line that's under the letter.

#### leehuan

##### Well-Known Member

Some of the math tutors\lecturers at USYD refer to the arrow notation as the "Russian way" of writing it. Apparently the normal westernised one is basically a squiggly line that's under the letter.
I guess that's just for the vector a etc.

If you got given a vector as defined by ray AB though or something, then well you need the arrow above no matter what.

##### -insert title here-

I write with a half-arrow.

#### leehuan

##### Well-Known Member

I write with a half-arrow.
Oh that, so do I. Who the hell has the time to put in the complete > when you can just use \

##### -insert title here-

Oh that, so do I. Who the hell has the time to put in the complete > when you can just use \
Code:
\overset{\rightharpoonup }{A}     \quad     \overset{B}{\leftarrow}
$\bg_white \overset{\rightharpoonup }{A}\quad \overset{B}{\leftarrow}$

This is for your sake, and possibly mine if I ever have to use vectors on BOS.

Lol, an italicised backward slash is a vertical line. This is amusing.

#### leehuan

##### Well-Known Member

Ah thanks. If I forget I'll just consult daum though. I've only recently begun typing LaTeX myself without any other software

$\bg_white \overset{\rightharpoonup }{AB}$

I use a swiggly line under stuff like b but when I refer to a vector with labelled endpoints I do that

#### Flop21

##### Well-Known Member

How do I do the last parts of these questions. I understand the rest, but have no idea what to do when it comes to throwing in epsilon in there (the last questions/s).

#### InteGrand

##### Well-Known Member

How do I do the last parts of these questions. I understand the rest, but have no idea what to do when it comes to throwing in epsilon in there (the last questions/s).

$\bg_white \noindent You need to find an M\equiv M(\varepsilon) (so it depends on \varepsilon) such that if x>M, then |f(x)-L|<\varepsilon.$

##### Cult of Personality

How do I do the last parts of these questions. I understand the rest, but have no idea what to do when it comes to throwing in epsilon in there (the last questions/s).

i think you should ask the maple consultant that's on tomorrow morning

i hear he's pretty awesome