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anonymous
 one year ago
I need someone that's good at matrices!! PLEASE HELP :'(
anonymous
 one year ago
I need someone that's good at matrices!! PLEASE HELP :'(

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I've been doing math all day and this is my last problem and I've never seen one like it before please help!!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@iambatman @jigglypuff314 @Preetha

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Can you post the "illustrated motion?"

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0oooh! I didn't even see it yes I will @mathmate

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2So this is a clockwise rotation about the origin, right?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Sorry, counterclockwise rotation about the centre of 90 degrees per frame.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0counterclocwise right?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2There is a matrix for r90. Do you know it by heart, or do you use the general matrix to rotate angle \(\theta\)?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I've never done rotated matrices before! I never learned it I don't know why they gave me this problem... please just show me step by step how you would do it

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Have you done translation matrices?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0no... the furthest I've gone is inverted matrices...

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2So you know how to multiply a matrix?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2A rotation matrix R (in 2d) is a 2x2 matrix, when premultiplied to a 2x n matrix will rotate the n sets of coordinates by an angle theta.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2R= cos(theta) sin(theta) sin(theta) cos(theta)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so with this problem...?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2and the points matrix would be x1 x2 x3 x4... xn y1 y2 y3 y4 ... yn

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2We'll call the points matrix Pn (for n points). So create the R matrix for +90 degrees, and the P matrix for the pattern required.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Each multiplication will rotate Pn by 90 degrees, CCW.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2For eight frames, you will multiply eight times. so RRRRPnPnPnPn with bring you back to the original position. Do that again will give you 8 frames.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok I'm a bit lost... how would I write the matrices?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2They were both given earlier, R, and Pn. The multiplication is only RRRRP

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0oooh! alright I see. so how would the finished problem look?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Do you find the matrices? I did not format them.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes I see, where you said the points matrix, and R

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2So to rotate 90 degrees, it's RP,. Say \(P=(2,1)^T\) and R 90 = 0 1 1 0 by subst. cos(90) and sin(90). So multiply 0 1 1 0 by 2 1 you'll get 1 2 get the idea?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2(sorry for the sloppy formatting)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok... the formatting is a little hard to follow but I think I get it...

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so is that the answer to my problem?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Not yet, you need to create Pn to represent the 4 points, then you can do the rotations.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0can you show me? @mathmate

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0better formatting like this?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0you have been soooo extremely helpful I wish i could thank you more!

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2The shape is made up of 4 points at frame 1. You make a 2x4 matrix to represent the 4 points, then premultiply by R, you'd get frame 2. But check the results!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0can you show me what the matrix would look like?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I'm sorry I'm not very smart :(

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2dw:1433211807693:dw Dont understimate yourself! :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0oh boy... I'm lost :( can you show me the next one so I can see the changes?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.20 2 ... 1 3... for all 4 points

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I'm so sorry to ask this... and you can of course say no, but I'm supposed to show my work, its late, I've been doing math literally all day... could you please show me what the answer / end result would look like so I can be done?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2I am sorry I cannot do that. But I think you are able to solve the problem if you can identify the vertices of the shape, and do matrix multiplication. I can help you check when you finish, or attempted.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I'm just going to leave it like that and get half credit, thank you for your help.
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