Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
#101 Re: Help Me ! » Understanding Ratio to Scale ? » 2013-04-13 16:10:58
hi SuperLynx
27:24:7 cannot become 7:9:? because there is no consistent ratio here.
To reduce from 27 to 7 you need a multiplier of x(7/27)
Apply that to 24 and you will get 24 x 7 /27 = 8 x 7 / 9 = 56/9 = 6.2222
You will have to choose one pair to get the multiplier from that and then apply it to both the other numbers.
eg 7 x 7/27 = 1.82 would then be the third measurement giving 7 : 6.2 : 1.8
or using 24 --> 9 makes a multiplier of x 9 / 24 and the ratios are then (27 x 9/24) : 9 : 7 x 9/24
In general the multiplier is x (new value) / (old value)
Hope that helps,
Bob
I need to divide 7/27 then apply that to 24 ? I'm not following 
#102 Re: Help Me ! » Understanding Ratio to Scale ? » 2013-04-07 06:35:08
Where did you get the multiplier of X ?
#103 Re: Help Me ! » Understanding Ratio to Scale ? » 2013-04-05 04:34:21
I have to re-surface this old thread.
Suppose I have a book, that was designed at 27 inches across / 24 inches tall / 7 inches think. Obviously a book for a giant, not for a human to read. How I calculate the ratio so the book is; 7 inches across / 9 inches tall / inch thick ?
#104 Re: Help Me ! » Math Books from Earlier Grades » 2012-10-03 10:44:36
I haven't touched this math in, well, about 15 yrs And what I learned I forgot, some of it, not all, now I want to get my brain going, I'm going to have to start with the fundamentals, and what vectors and algebra is, and dot matrix etc, I'd prefer if there was a book with picture examples, of all the different types following the math.
Any more suggestions would be welcome, we all know there is a wealth of math books, suggestions in this case are needed
#105 Re: Help Me ! » Math Books from Earlier Grades » 2012-10-02 10:34:35
I prefer books, any more suggestions are welcome, give me something to decide on
#106 Help Me ! » Math Books from Earlier Grades » 2012-10-02 01:30:09
- SuperLynx
- Replies: 4
Hi, I'm in need of Grade 8 / 9 / 10 Trigonometry & Algebra math books, any recommendations from books you learned at school or bought when you were younger ?
#107 Re: Help Me ! » Understanding Trig and Algebra » 2012-09-24 11:40:21
Isn't that vector 2,7 ?
#108 Re: Help Me ! » Understanding Trig and Algebra » 2012-09-24 01:15:21
This is going to sound like a dummy, which I am since I have forgotten some of this stuff. Do you know any real basics teachings so I can build from that ?
#109 Help Me ! » Understanding Trig and Algebra » 2012-09-23 15:47:45
- SuperLynx
- Replies: 5
Hi. I'm looking for some help in understanding Trigonometry and Algebra. Specifically, vectors, matrices & scalars. I hope someone can help me, I have searched on the subject, although nothing I could understand. How do you multiple vectors, what is a dot product, I suppose best to start with that, I've already begun learning, but any resource or your own personal explanation would be helpful.
#110 Introductions » Who I am - Super Lynx » 2012-07-13 18:31:54
- SuperLynx
- Replies: 3
Hi, I'm Super Lynx. I'm more of an Artist, but I'm learning programming, programming math and a few other things, slowly but steady. I invite you to visit my web site at http://www.thecreativesheep.ca and tell me what you think, I'm open for comments and suggestions. I hope to land a Job in Graphic Design or Game Design.
#111 Help Me ! » Understanding a Coordinate system » 2011-06-16 00:15:00
- SuperLynx
- Replies: 2
Hi, I'm looking for someone who understands UV coordinates ?
#112 Re: Help Me ! » Reduction in Percentage ? » 2011-03-19 14:45:55
Thank you I knew it was division just wasn't sure if the result would be the right number, now I know for good
#113 Help Me ! » Reduction in Percentage ? » 2011-03-19 11:31:03
- SuperLynx
- Replies: 3
I have a file that is 600K and it was reduced to 260K. How can I find out what that reduction is in percentage ?
#114 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-26 12:34:47
R would work very well for that, in combination with geometry related resources that tell what matrix operations and manipulations need to be performed for the geometry manipulations you wish to perform.
What is this R program you speak of ???:)
Linear algebra is a fairly advanced topic. If one hasn't mastered the recommended prerequisite topics, the subject matter can be extremely challenging. (It isn't necessarily easy even if you have mastered prerequisite material.)
I can see, but I'm going to give it my best the PowerPoint tutorials that Bob Bundy posted some of them are quite good, does anyone have any more PowerPoint tutorials on a wide range of math subjects ?
No, not for the matrix A given in post #282, where a = 1, b = 2, , i = 9.
I don't understand what you mean, even though my answer is wrong 
As I watch some of these power point tutorials when I have questions I will post using latex to get my question more clearly written
#115 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-24 01:35:58
I don't have powerpoint.
#116 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-24 00:38:49
SuperLynx, that's the trick I use to remember the formula for 3×3 matrices. There are some tricks to make finding the determinant easier on larger matrices, but I don't recall exactly what they are at the moment. I'd have to reference my old Linear Algebra text, which isn't handy. I don't remember them because I don't manipulate matrices by hand regularly, and linear algebra is far less intuitive than working with scalars.
Should I stick with this trick for now or is their an easier one ?
If you want to learn about them, your best option might be to find your own text. You should be able to find an old edition for very little money, and it would likely be more productive than trying to find the information in Internet forums.
I've look for something I can understand, no such luck. What are determents anyhow ?
Once upon a time, my College Algebra professor once told us that manipulating matrices is something we would likely never want to do by hand, that calculators and computers are much better suited for the task. While my Linear Algebra didn't share that sentiment, I've found it to be generally true.
Personally, I'm a big fan of R (the free, open source statistical software package), which is designed for manipulating large matrices.
'R' ?!?!? My goal to learn matrices is I want to understand them for use in geometry and how they are used to manipulate geometry, I have a little easier understanding of 3x3 matrices but not of 4x4.
I would like to know was the answer I posted in #284 correct ?
#117 Re: Help Me ! » 3D Geo - Breaking apart what is going on [Road to Mastering Series] » 2011-01-24 00:33:25
I'll post a deeper explanation, maybe someone else can take a stab at it I know somewhat what is going on.
#118 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-23 17:29:35
All is number - That was more helpful it is a little awkward way to figure out how to do the math for a matrix, is there an acronym/abbreviation that one can remember for this, but I know there are many other ways to figure out a matrix 
I want to squeeze in a question about 4x4 matrix which is the following, how does 4x4 matrix come into use in geometry ? What is that extra row and column come into play ? If a 3x3 Matrix converted to scale of a geometric object of the first column that would be sX, sY, sZ that I understand.
#119 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-23 14:22:50
That is not correct. There are other methods to finding the determinant. I gave you that formula because I know you cannot follow anything else just yet. I wanted you to learn how to plug in to a formula. You are lacking essential skills and it is crippling you.
It is obvious to me that your algebraic understanding is not up to the task yet. That is why I wanted you to learn how to follow a formula first.
What you gave is one of many rules that can be used to find the determinant, that is what I wanted to know
For the time being I'll stick with this rule, what I'm curious about is why that rule is figured out as it is ?
I wanted you to be able to understand what a variable is. Jumping ahead is only making the task last longer. I do not mind, I like talking to you but what about you. You must get some fundamental math before you run to what a determinant and what it is good for.
I'm not jumping ahead, I'm trying to make sense of it my own way !
I saw what you did up above. Concantenating numbers instead of multiplying them. You need to learn what an algebraic formula means. Now Bob, Howard and gAr do not need any help. They know algebra. Please ask the right questions when speaking to them.
I am trying to learn what an algebraic formula means, I never said that bob, Howard, gAR needed help they were helping me and I had no problems with what they were saying like I said I was trying to make sense of it. 
#120 Help Me ! » 3D Geo - Breaking apart what is going on [Road to Mastering Series] » 2011-01-23 11:40:03
- SuperLynx
- Replies: 2
The yellow lines represent vectors the green lines represent scalars and point normal and point position returns the position of each point on a 3D geometric object. I'm hoping someone can help me break down what is happening here and I understand how the multiple and add nodes work but what I don't understand is what the math is doing.
#121 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-23 11:32:46
The rule I had posted in message #272 is the rule that must be followed to find the determent of a matrix ? I find it odd that there is no sequence to finding the determent, it seems like a random rule.
I've started another thread on the Geometry question as well.
#122 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-23 06:57:54
How are you picking those numbers out ? Break it down a little further, afterwards I want to show you something related to Geometry math, both co-inside with each other so I hope you can help as well.
#124 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-23 04:28:23
This is the rule that must always be followed, gAR could you break down the minors.
Correct using the rule I quoted ?
This is for a 3x3 matrix, correct ?
#125 Re: Help Me ! » Math Terms - Visually Described ? » 2011-01-22 17:11:24
I'm not following... !