Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

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#51 Re: Help Me ! » Unit Circle Pythagorean Identities » 2012-03-21 20:44:37

No, thats perfect thanks. I wrote that it's always true and I just wanted to make sure what I wrote was accurate. Thanks

#52 Help Me ! » Unit Circle Pythagorean Identities » 2012-03-21 08:11:01

amberzak
Replies: 2

I'm finishing my essay on the Unit Circle, and I just have a really quick question if someone could oblige.

The pythagorian identities in the unit circle state that, for example, cos^2 theta + sin^2 theta = 1. Does this work when you move all the way around the circle (for example, when the angle is 90 degrees, the triangle in the circle is just a line, so cos will be 0)

#53 Re: Puzzles and Games » The Professor and the Student » 2012-03-19 20:24:46

Well, speaking as a trainee teacher, the professor is always right smile

#54 Re: Help Me ! » Geometric Progression? » 2012-03-19 04:19:33

My tutor said I'd actually gone further with the investigation than he'd expected, so even though I didn't quite get the progressions part, it was still good enough to keep my grades in the higher section, so yay.

#57 Re: Help Me ! » Geometric Progression? » 2012-03-17 22:03:54

Bob, you are a genius. big_smile

To both bob's, I really really appreciate your help with this. Geometry is a subject that I normally excel at, and as a result I feel the pressure when I just don't see any pattens or anything.

#58 Re: Help Me ! » Geometric Progression? » 2012-03-17 21:46:17

Yep. If I want to find the length of the new square: a^2+b^2 = c^2

I love pythagoras tongue

All my other sketchpad work is already at the top mark, and they take our work as a whole (it's partly creating resources as well as finding out for ourselves) so I am thinking that maybe I shouldn't be trying to work out all the complex maths if I don't really have tim (it's due tomorrow and I have an essay due Tuesday).

That maybe I should just comment that it is in successive geometric progression and just give one example

#59 Re: Help Me ! » Geometric Progression? » 2012-03-17 21:27:36

He titled the work Geometric Progressions, but the assignment was given after a lesson on fractals.

#60 Re: Maths Is Fun - Suggestions and Comments » Pi » 2012-03-17 21:06:44

I love it.

Can I just say, Maths is Fun, that your website is amazing (only just found the accompanying forum) and I've been using it when I tutor to try and get my pupils to look on your website because it is so informative and easy to understand.

#61 Re: Help Me ! » Geometric Progression? » 2012-03-17 20:56:48

Bob. I logged off just as you came on lol. I got too tired.

Yeah, that's how I worked it out. You have to keep the dividing fraction the same on each shape. So for example, on my first square I have kept it the same distance in fraction for every smaller square in that shape.

Oh, and bobby, thanks.

#62 Re: Help Me ! » Geometric Progression? » 2012-03-17 06:58:08

The exact wording isn't very clear. It says
Take a reqular ploygon
Dissect it in a way that leads to a smaller version of the same polygon
Repeat with the new polygon - the process can go on for ever.

The then gave some examples, the picture bobby kindly posted for me (without the red lines) demonstrates his example.

Then he writes:

What happens to the areas (ratios?)
What happens to the lengths of the sides?
Experiment with different starting polygons - do you always get the same ratios?

That's it. All he wrote. I'm doing it on geometer's sketchpad (which isn't the easiest program to use doing this)

Thanks guys for all your help.

Bobby, how did you work out those figures? We've not actually been taught any of this.

#63 Re: Help Me ! » Geometric Progression? » 2012-03-17 03:44:05

Yeah. That is the triangle I dissected at a third.

So you think you have the maths?

I don't even know how to google this to get some information on it. I know it's like fractals or something.

The red lines are just to show you that the lengths are not just cut, if you understand me

#64 Re: Help Me ! » Geometric Progression? » 2012-03-17 03:39:08

It's sort of like that bob, except I have 4 versions of each shape, each one where the dividing spiralling is at the same distance - so one is always at the half way mark, the next is always a third of the way in etc. And it's Square, Triangle and Hexagon

The actual question stares What happens to the areas? (ratios)
What happens to the lengths of the sides?
Experiement with different starting polygons - do you always get the same ratios?

Maybe I'm making it more complicated than it has to be, and I don't need to find a link with each separate shape, only that within each shape the areas have the same ratios. But I am aiming for the top marks

#65 Re: Help Me ! » Geometric Progression? » 2012-03-17 03:34:07

Go onto flickr and search amberzakfilmsuk for people. It's the only photo on my page, and it's a triangle.

#66 Re: Help Me ! » Geometric Progression? » 2012-03-17 03:20:08

I have the link. It most let me post it
Still keeps telling me I have to be a member to post links.

#67 Re: Introductions » Hi all » 2012-03-17 03:19:00

THanks for the welcome Bob.

Why can't I post pictures yet? I have more than 10 posts.

#68 Re: Help Me ! » Geometric Progression? » 2012-03-17 03:13:27

I found the ratios by dividing the bigger area by the smaller area.

The picture below is an example of what I am doing. This is the triangle directed at half way along the edge The problem with what you are saying, bob, is that as you can see by the red line, the length of P-Q is more than 1 third and less than 2 thirds of the length. So it isn't as easy a ratio as you said.

THIS IS REALLY INFURIATING. I still can't post pictures, but I've done 10 posts.

I really need you to see it or it won't name any sense

#69 Maths Is Fun - Suggestions and Comments » No links until 10 posts » 2012-03-17 03:04:23

amberzak
Replies: 1

I understand that you need to protect against spam. I'm a moderator on a writing forum where we have big problems with Spam. But could you have another way of posting pictures that doesn't need a link, or else introduce posting links after 5 posts. I've found myself posting pointless posts just so I can show a picture to get some help.

#71 Guestbook » Happy st. Patricks Day » 2012-03-17 02:59:18

amberzak
Replies: 1

Yep, it's st. Patricks day in the UK and Ireland

#72 Jokes » Pi and i have a conversation » 2012-03-17 02:58:09

amberzak
Replies: 3

Pi to i: Get real!
i to Pi : Get rational!

#73 Re: Help Me ! » Time Management for Exams... » 2012-03-17 02:46:30

My advice (speaking as both a trainee teacher and as someone who who has studied for exams in the past) is don't try and do all the mock exams. Prioritise using two factors - firstly how soon is the exam and secondly how well do you know the topic. If you do one mock exam and you aced certain elements, but you needed improvement on other areas, then when you do the next mock paper, concentrate on the areas you needed more time with.

Don't burn yourself out before you get to the exams.

#74 Introductions » Hi all » 2012-03-16 21:50:51

amberzak
Replies: 7

I am amberzak. I am going to start training as a maths teacher in September, and I am currently doing an intensive maths enhancement course. We have lots of deadlines looming.

I've not Studied maths since I was at school, so there are some things that may seem basic where my knowledge is missing. This is why I am on the maths enhancement course.

I am also happy to help people here as well.

#75 Re: Help Me ! » Geometric Progression? » 2012-03-16 21:46:30

Bob. That's it.

Bobbym, I can't put my table up. It won't let me put images up yet. I'll try and write it.
                                               
Triangle dissected at a half - Area Ratio 4, Length ratio 2
Triangle dissected at a Third - Area ratio 3, Length ratio 1.73
Triangle Dissected at Quarter - Area ratio 2.29, Length Ratio 1.51
Triangle Dissected at a Fifth - Area Ratio 1.92, Length ratio 1.39

Square dissected at a half - Area Ratio 2, Length ratio 1.41
Square dissected at a Third - Area ratio 1.80, Length ratio 1.34
Square Dissected at Quarter - Area ratio 1.60, Length Ratio 1.26
Square Dissected at a Fifth - Area Ratio 1.47, Length ratio 1.21

Hexagon dissected at a half - Area Ratio 1.33, Length ratio 1.15
Hexagon dissected at a Third - Area ratio 1.29, Length ratio 1.13
Hexagon Dissected at Quarter - Area ratio 1.23, Length Ratio 1.11
Hexagon Dissected at a Fifth - Area Ratio 1.19, Length ratio 1.09


Sorry I didn't reply last night. I was so exhausted.

Thanks

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