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#51 Re: Euler Avenue » Gurth's Fractals » 2010-07-12 03:18:52

I would like to see the code please, looks great smile

#52 Re: Help Me ! » Optimisation Problem » 2010-07-06 21:51:47

Hi Guys

Hi Bobby, thanks for the help and the links.

So busy at the moment with this prep work. Trying to get all this stuff into my head so I know it rather than having to refer to the book. At the moment I am just jumping back and forth between the chapters, not sure if that is the best way to go or not.

#53 Help Me ! » Optimisation Problem » 2010-07-02 01:58:30

DaveRobinsonUK
Replies: 36

I have a problem that I can't seem to work out, or at least get started with.

Anyway here it is.

There is £120 to spend on a fence to enclose a garden. Fencing for 3 sides costs £2/m the other side costs £3/m.

a) Given the rectangle has dims x by y show that

b)Hence show that

c)Find the maximum area of the garden.

Don't know what it is with optimisation, I can do the normal differentiation problems and most of the optimisation problems, every now and then though.

#54 Re: Help Me ! » Sequences » 2010-06-26 20:45:00

50-50 is SOUND!!

I think I will have Emo Phillips or maybe Sam Elliot and for my dizzy but inspirational wife I will have Sophia Loren, or maybe Audrey Hepburn, who will star as an urn which has a telepathic link to the afterlife (presuming she was cremated, if not old Sam will have his work cut out for him pulling the coffin about town).

Sweden sounds cool too, though we will have to take our own beer. I don't fancy paying $40.00 every time we need more. Although money, should not be a problem with our Nobel coin.

Superb, thats cheered me up no end.

#55 Re: Help Me ! » Sequences » 2010-06-26 19:11:12

funny..

I was just thinking about this formula before.

#56 Re: Help Me ! » Composite Functions » 2010-06-18 08:32:40

Yes, forums are very cool for those times.

Got my new calculator today, been playing around with that. Also very cool.

Maple in my pocket smile

#57 Re: Help Me ! » Composite Functions » 2010-06-17 22:09:11

I think you are right, I am quite a creative and visual person and it does always help
to have good visual definition. I like to be able to see things work.

It does help to see as many different explanations as you can get your hands on. I have
found a lot that I have seen one method and then later found a much more elegant and
efficient way of doing things.

About the same time I got the Stewart book I borrowed a book from my uni library called
'An Introduction to Mathematical Logic' by Gerson B Robison in an attempt to better understand
Predicate Calculus and finding that it lost me about half way down the first page.

I should have another look at that some time.

#58 Re: Help Me ! » Composite Functions » 2010-06-17 06:02:25

Darn.. I thought I saw it for a second then, when checking and looking a the
answer in the book, so I worked it through but just came up with the same

I don't know, maybe it is just something that slipped past the copy readers.

#59 Re: Help Me ! » Composite Functions » 2010-06-17 05:47:45

It's quite big isn't it.  big_smile Very beautiful too aesthetically as books go. Although I have only recently
been in a position to understand it, it has always been on of my prized possessions. I always
wanted to understand its contents which is another of the driving factors behind all this work.
There are many.

You recommend checking out the others then?

I think even if the solutions are different, the expainations and examples are top notch.

#60 Re: Help Me ! » Composite Functions » 2010-06-17 00:40:53

Hi Bobby

Sorry for the delay, had to nip out to Chichester.

The book is Calculus - Concepts and Contexts, by James Stewart.

I got it about 10 yrs ago and have only just started using it smile

#61 Re: Help Me ! » Composite Functions » 2010-06-15 19:45:57

Hi Bobby

Thats really bad, especially when it is vindictive. There should be no room for that.

#62 Re: Help Me ! » Composite Functions » 2010-06-15 19:43:39

Anyway.. Back to the origianal problem.

I went through the 4 questions on MIF, thought cool and went back to my book
and came straight across this, I don't get the same answer and I ran it through
Maple and it gets the same answer I do, so I am stuck again.


find

I and Maple get

the book on the other hand gets

#63 Re: Help Me ! » Composite Functions » 2010-06-15 19:28:50

Cool... It does say that it is a common mistake people make, and I did read that in the local parish rag wink

Must admit that is the first time I have read any of that, with me not really being qualified to write about
anything. I just use it for a reference.

#64 Re: Help Me ! » Composite Functions » 2010-06-14 23:17:21

I don't know if there is any truth in it for definate, though I have read in the past that the documents have
an owner. I think it is to guard against people purposely making changes that are false. I suppose it makes
sense from that point of view, but not if the information they are putting up there is incorrect in the first place.

#65 Re: Maths Is Fun - Suggestions and Comments » Function Grapher and Calculator » 2010-06-14 22:50:34

Very nice, is it done in Flash?

How do you get flash to draw arbitrary curves from the built in AS graph functions?

#66 Re: Help Me ! » Composite Functions » 2010-06-14 22:47:50

I must confess I cheated a bit and used a thesaurus

#67 Re: Help Me ! » Composite Functions » 2010-06-14 22:38:25

It's like you say, you can put amendments to increase the accuracy of the document and if the person
who originated it doesn't like it for whatever reason (probably due to their ignorance being exposed) they
can change it back. That doesn't say much for the overall accuracy of the information contained on the site.

Still, I suppose it has it's uses, as long as you don't take it too seriously. "Impedia" smile

Crockipedia, Erratipedia, Faultipedia, Confusipedia smile

#68 Re: Help Me ! » Composite Functions » 2010-06-14 19:55:30

Hi Bobby

Very Cool, I was also glad of the page on Domains and Ranges. My book has info about this
though it does not mention Codomains.

#69 Re: Help Me ! » Composite Functions » 2010-06-14 19:33:15

Hi Bobby and Soroban

Ahh, I see what I have done. For some reason I have added the 2 to make 10, rather that
subtract to get 6.  So the 3 can't be taken out of the brackets completely, leaving that 10
instead of the 2 that it should be.

Thanks for the link Bobby it's great and I have also been looking for good notes on set builder
notation. You can hardley understand anything from Wikipedia.

#70 Help Me ! » Composite Functions » 2010-06-14 06:45:05

DaveRobinsonUK
Replies: 28

Hi Guys.

I have just learned about composite functions in my book and followed it, what I thought was o.k,
then I had a go at one of the questions and my answer is out, what looks to be slightly, though
I have a feeling is quite a way out.

Here is the question

find the composite function

where
and

I get

though the book gives

bit of a bummer "so close, yet so far";)

Thanks David

#72 Re: Help Me ! » Scientific Notation » 2010-05-30 21:17:42

It was great, until I was literally handing my passport over to the baggage handler when a woman leant over and wispered in her ear. She then said that all flights from Corsica to UK we cancelled for at least a week. There was a huge panic and a run on the airline desk. Luckily we have a house over there, so we just went home and had an extended holiday.

Took Emma to the beach everyday and made sand castles, and studied logarithms in the afternoons. Log fires in the evenings. Very nice smile

You off anywhere this year?

#73 Re: Help Me ! » Scientific Notation » 2010-05-30 20:25:05

Ahh

I see now.

Unit for Acceleration (m/s)/s

Derived units.

Cool, happy now smile

#74 Re: Help Me ! » Scientific Notation » 2010-05-30 20:02:12

Hi Bobby

Thanks for that, I didn't know about the accuracy. That's handy to know and makes sense too, kind of like Amdahls's Law for functions, although none of my tutors have ever mentioned it.

Just shows you that you should always consult others rather than taking one persons word for it.

#75 Re: Help Me ! » Scientific Notation » 2010-05-30 19:05:45

Hi Bobby and ZHero

Yes, I got

, it asked for the answer to 3d.p.

How is it that s is -2 though kg is -1. Does it just denote that m/s is a ratio and kg is a definite unit?

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