a Q from homework (1 Viewer)

[Sirius Black]

A curve y=f(x) is defined by xy-y²=c² where c is a non-zero, positive, real number.

a)Discuss what ahppensas x--> +/- infinity
b)Find dy/dx
c)Sketch the curve

thanx

 

[alphatango]

You wouldn't care to show *any* of your own work at all, would you? It makes others (well, me at least) a lot more enthusiastic about helping if there's some evidence that you've done some thinking about the question. Even if you didn't get anywhere, tell us what your thought processes were...

There are a couple of different areas brought into this question...not only your curve sketching skills but also your implicit differentiation skills, for example. At least let us know which areas you're having trouble with (be specific, not "the whole thing" )!

 

[maths > english]

Solution attached as 2 images

 

[Trev]

gees ur writing is neat enough, what topic is this in? (graphs?) which textbook?

 

[Slidey]

Trev: Graphs. It's a pretty generic question. Not necessarily easy - just generic. Part a is 3unit curve sketching, part b is obviously textbook 4unit implicit diff, part c is 4unit addition of ordinates.

 

[Trev]

ook thanx slide, i hope we havent done this yet in 4u =S i need to pay attention more

 

[Slidey]

Um... I think you'd know if you did - graphs is an entire topic.

 

[Trev]

no no no, i mean, i hope i haven't missed doing parts of this question, we are doing graphs now, but i'm a bit behind =S
i am up to exercise 1.5 (i think) in cambridge, would this question be before or after where i'm up to? if u get wat i mean.....

 

[Slidey]

Well, addition of ordinates should be the FIRST thing you do. Implicit differentiation is easy, but is usually the LAST thing you do.

So go and revise addition of ordinates, I guess.

 

[Sirius Black]

Actually I have done all the parts of this question but i just couldn't understand what is the purpose of finding dy/dx but not use it.

 

[Slidey]

Actually I have done all the parts of this question but i just couldn't understand what is the purpose of finding dy/dx but not use it.

On that note, what was the purpose of drawing the graph? In both cases, the answer is: so that you can practice or so that you can be tested.

 

[~ ReNcH ~]

Well, addition of ordinates should be the FIRST thing you do. Implicit differentiation is easy, but is usually the LAST thing you do.

So go and revise addition of ordinates, I guess.

Addition of ordinates is in the 2U Fitz. book...is it actually part of the 2U syllabus? I think I've only ever seen it tested once in an Ext 1 paper.

 

[Slidey]

Addition of ordinates is a 4 unit topic only, however it is a very easy topic and I wouldn't be surprised if it were taught to 2 or 3 unit students. Examining them on it is another thing - it's not part of their syllabus. If they were lead in, then I suppose it could be considered component B.