Question (1 Viewer)

[dark_angel]

What are Injective and surjective functions, i cant find them anywhere in calculus 4th ed. by stewart.

also, what is R cubed? (R as in the symbol for real numbers?)

this is for week 4 btw from the syllabus, and week/topic layout math1901

in full:

week 4: Working in R^3. Curves and surfaces. Functions of 2 variables. Level curves. What chapter is this refering to?

 

[SeDaTeD]

Injective functions and surjective functions are just other names for on-to-one functions and onto functions. R^3, working in three dimensions, ie. working with functions of 2 variables f(x,y). Level curves are the curves defined by f(x,y)=c, for any constant c.

Sorry I dont have Stewart Calculus. Do you think it's worth getting? I have Calculus and Analytic Geometry 6th ed, Thomas and Finney, which is a pretty old book hat I borrowed from my uncle. Seems to have everything covered.

 

[dark_angel]

Injective functions and surjective functions are just other names for on-to-one functions and onto functions. R^3, working in three dimensions, ie. working with functions of 2 variables f(x,y). Level curves are the curves defined by f(x,y)=c, for any constant c.

Sorry I dont have Stewart Calculus. Do you think it's worth getting? I have Calculus and Analytic Geometry 6th ed, Thomas and Finney, which is a pretty old book hat I borrowed from my uncle. Seems to have everything covered.

ahh ic ic, its just when i tried the index, it didnt have those references to functions.

I cant answer that question, mainly because i'm just starting the text, but also because i borrowed the 4th ed. from fischer, not 5th, they dont have it.

but the only reason i borrowed it was because it was the text used last year, along with some others.


I borrowed another old book which introduces matrices and vectors, which i am learning in tandum with calculus. Thanks for the recommendation though, i might borrow that book also.

 

[dark_angel]

Injective functions and surjective functions are just other names for on-to-one functions and onto functions. R^3, working in three dimensions, ie. working with functions of 2 variables f(x,y). Level curves are the curves defined by f(x,y)=c, for any constant c.

Sorry I dont have Stewart Calculus. Do you think it's worth getting? I have Calculus and Analytic Geometry 6th ed, Thomas and Finney, which is a pretty old book hat I borrowed from my uncle. Seems to have everything covered.

btw i was just wondering, are you going to do any postgraduate studies?

also, have you finished first year maths? I mean it dosent look too hard, the first couple of topics weve completed in ext 2, but taylor series and multiple integrals look very interesting.

i'm hoping to finish as much maths as i can before i start uni.

 

[SeDaTeD]

Nope, I haven't started uni yet. However I think I would be familiar with most first year calculus. I currently have a decent grasp of the stuff covered in that textbook, bar vector analysis. As for postgrad, I'm not really thinking that far ahead, but I wouldn't mind. In my opinion, first year maths is way boring. The interesting stuff starts in second year.

 

[Bob.J]

Sorry I dont have Stewart Calculus. Do you think it's worth getting? .

it's worth getting, you'll use it in 1st and 2nd semester on 1901, 1903 and then you'll need it in 2nd year and possibly 3rd year as well

 

[dark_angel]

it's worth getting, you'll use it in 1st and 2nd semester on 1901, 1903 and then you'll need it in 2nd year and possibly 3rd year as well

hi bobj! What about 1902, do we just use the lecture notes for vector analysis/linear algebra, or is there a book i can borrow??!!?

 

[Bob.J]

hi bobj! What about 1902, do we just use the lecture notes for vector analysis/linear algebra, or is there a book i can borrow??!!?

linear alg is pretty easy in first year (the exam can be tricky), so you only really need the lecture notes and course notes from kopystop. There are textbooks but you'll be wasting your time reading those.

 

[xiao1985]

hm... stewart... i got it but i neva used it in first yr... all u really need in first yr maths is lecture notes, attendance (ok a fwnd of mine didn't go to any of the stat lecture and only attended 2 tutorials and still manages 89... me on the other hand spent 23 more hrs than her on stat, got one mark more... wut a world ) and thorough study of past exams n tutorial sheets will suffice...

btw bob.j, i thought u belong to usyd??!! ='(

 

[SeDaTeD]

Hmm, how much do they enforce the 'you must attend at least 80% of tutorials' rule, or something along those lines?

 

[thaoroxy2001]

What the? what's wif all these ppl looking through the textbooks and lecture notes already??....you're all freaking me out .......I feel so unprepared for Uni coz I've only got one book (physics)!!

hmm...lemme guess.....u all got over 99 for UAI right? ''

 

[dark_angel]

What the? what's wif all these ppl looking through the textbooks and lecture notes already??....you're all freaking me out .......I feel so unprepared for Uni coz I've only got one book (physics)!!

hmm...lemme guess.....u all got over 99 for UAI right? ''

no i didnt [get over 99]

edit: i need good marks for med........

 

[Bob.J]

hm... stewart... i got it but i neva used it in first yr... all u really need in first yr maths is lecture notes, attendance (ok a fwnd of mine didn't go to any of the stat lecture and only attended 2 tutorials and still manages 89... me on the other hand spent 23 more hrs than her on stat, got one mark more... wut a world ) and thorough study of past exams n tutorial sheets will suffice...

btw bob.j, i thought u belong to usyd??!! ='(

actually yeh, first year you don't really have to use the stewart textbook. First year is all a blur to me now. However, i definitely used it a lot in vector calculus and complex variables, MATH2901 (the exam was an absolute bitch!)

yeh, sorry xiao, I am now the property of UNCLE. Bob's your uncle lol

 

[Bob.J]

What the? what's wif all these ppl looking through the textbooks and lecture notes already??....you're all freaking me out .......I feel so unprepared for Uni coz I've only got one book (physics)!!

hmm...lemme guess.....u all got over 99 for UAI right? ''

it's your first year of uni, don't overwork yourself.
Besides you'll be overworked plenty in 2nd year being med science, you'll do about 30-33hours a week. Then it'll drop to like 15 hours a week in 3rd year

 

[dark_angel]

actually yeh, first year you don't really have to use the stewart textbook. First year is all a blur to me now. However, i definitely used it a lot in vector calculus and complex variables, MATH2901 (the exam was an absolute bitch!)

yeh, sorry xiao, I am now the property of UNCLE. Bob's your uncle lol

hahaha i'm learning matricies {i cant spell :uhhuh: }, they're fun!!! :uhhuh:

 

[Bob.J]

hahaha i'm learning matricies {i cant spell :uhhuh: }, they're fun!!! :uhhuh:

oh yeh
first year pure maths is cool
just be sure to be careful of 2nd/3rd year pure maths at the advanced level. It's crazy, like...CRAZY.
http://www.library.usyd.edu.au/exams/exam03/038027.pdf
http://www.library.usyd.edu.au/exams/exam03/038040.pdf

well depends on the person really, but I fancy myself an applied maths person.

 

[dark_angel]

oh yeh
first year pure maths is cool
just be sure to be careful of 2nd/3rd year pure maths at the advanced level. It's crazy, like...CRAZY.
http://www.library.usyd.edu.au/exams/exam03/038027.pdf
http://www.library.usyd.edu.au/exams/exam03/038040.pdf

well depends on the person really, but I fancy myself an applied maths person.

lol thanks for the links. I now have a new found fear of links with the words usyd, and exams

oh yeah, should i do statistics, or discrete maths, i want to do discrete, purely because i HATE statistics, and would rather eat worms or something of that sort, but the maths lecturer at enrolment said i would need it in physics?

id rather do discrete, but is it that advantageous to use it purely for physics, when perhaps i could be better of learning something that i liked, and looked forward too?

thanks

oh yeah did you move to newcastle now??!?!

thanks again

 

[Bob.J]

lol thanks for the links. I now have a new found fear of links with the words usyd, and exams

oh yeah, should i do statistics, or discrete maths, i want to do discrete, purely because i HATE statistics, and would rather eat worms or something of that sort, but the maths lecturer at enrolment said i would need it in physics?

id rather do discrete, but is it that advantageous to use it purely for physics, when perhaps i could be better of learning something that i liked, and looked forward too?

thanks

oh yeah did you move to newcastle now??!?!

thanks again

hello DA

do statistics, it opens up a wide path of choice in 2nd year
discrete maths is kind of useless as it is not required as a prequisite in anything. Whereas MATH1905 is required for 2nd year stats etc and well the knowledge of stats is more useful than discrete maths. Stats is good if you're interested in getting a major in statistics ie. entering the financial world, which you're not going to do. So if you feel discrete is what you want then do it.

Besides, this is 2nd semester so you can change it whenever you want.

Not in newc yet, going up there this weekend i'll try to take pics and post em so you can all see what it looks like

EDIT- I had previously chosen discrete too but the guy at enrolment told me to do statistics because it was more useful and that we could do discrete maths in 2nd year if we really wanted to. The lecturer for adv stats is really shit, and he makes you buy his book. I kept wondering if the guy told me to do stats because there simply wasn't enough students doing it and they wanted more students to fill up the lectures...maybe

 

[thaoroxy2001]

it's your first year of uni, don't overwork yourself.
Besides you'll be overworked plenty in 2nd year being med science, you'll do about 30-33hours a week. Then it'll drop to like 15 hours a week in 3rd year

30-33hrs a week? *faints*

 

[thaoroxy2001]

no i didnt [get over 99]

edit: i need good marks for med........

ahhh...I see...Good Luck =)