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maths help (vectors)

maths help (vectors)

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Originally posted by angie88
to be honest... I have no idea what you're talking about 🙁
Thanks though.

Peachy-it's 4. the C has to be the negative thing... draw a sketch and you'll see.
Sorry. I misunderstood what the problem was...

You have the coordinates of 2 vertices of a triangle in 3D dimensions, and you have also as data the coordinates of the baricenter of the triangle. and you must to find the coordinates of the third vertice.

Is it so?

If you are in a hurry, I can't help. Sorry. 😳

I have a lot of work pending of a solution just now. But if you give me a pair of days, I'm sure i'll find the time to give you the answer to your problem.

In the midtime, I hope you will find the simple solution this problem has.

Cheers!

P.S.: going to dive my only neuron that it's still working on my own problems. Anyway, you are welcome.

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Play with this till we figure it out...

http://www.falstad.com/vector3d/

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Originally posted by Peachy
Play with this till we figure it out...

http://www.falstad.com/vector3d/
Neat!

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Originally posted by Nordlys
Neat!
🙂

http://www.falstad.com/mathphysics.html

tons of fun here..

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Originally posted by Peachy
🙂

http://www.falstad.com/mathphysics.html

tons of fun here..
Bookmarked! 🙂

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Originally posted by Peachy
🙂

http://www.falstad.com/mathphysics.html

tons of fun here..
aaaggghhhhhhhhhhhh make it stop make it stop

im trying to forget all that crap

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Originally posted by Peachy
Play with this till we figure it out...

http://www.falstad.com/vector3d/
hadn't seen this in a while though 🙄

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angie88, I used to be bright fruit at some point. Done that kinda maths before.. now a days, with no exercise, I have added on weight and fallen off the peach tree..

Did you try to work it out backward? Plot the triangle ABC then find mid-point S?

See if that matched.. otherwise, something is wrong.
All the best.

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I had to look this one up--back when I took geometry, dinosaurs still roamed the earth. 😕

http://en.wikipedia.org/wiki/Equilateral_triangle#Points.2C_lines_and_circles_associated_with_a_triangle

I think the measure you're refering to is called the "centroid" in this article. It is the intersection of the three "medians". The medians are the lines between the vertices and the center of the opposing sides. According to the article the centroid cuts through each median with a ratio of 2:1--twice the distance from the vertex to the centroid as from the centroid to the opposite face.

The center of AB is 2, 1.5, 0, thus the difference between S (0, 0, 4) and the center of AB is -2, -1.5, 4. S plus two times this difference is -4, -3, 12.

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Originally posted by angie88
Heya all you smart (and helpful/bored) people of rhp 😀
This not that important, but it's really bugging me, so if anyone has some time on their hands:
We had homework in maths for tomorrow. She already told us what the answer was, and we were supposed to see if we could figure it out by ourselves. Problem is, I have a different answer than she does, and I gave was C (-4|-3|12).
My answer was C (-8|-7|12).

Any opinions on this?
Thanks,
Angie
The point S can be given by (a + b + c)/3.

(It's not too hard to prove that, if you don't believe it).

So (1, 1, 0) + (3, 2, 0) + c = 3x(0, 0, 4)

So c = (-4, -3, 12)

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Originally posted by angie88
Heya all you smart (and helpful/bored) people of rhp 😀
This not that important, but it's really bugging me, so if anyone has some time on their hands:
We had homework in maths for tomorrow. She already told us what the answer was, and we were supposed to see if we could figure it out by ourselves. Problem is, I have a different answer than she does, and I ...[text shortened]... gave was C (-4|-3|12).
My answer was C (-8|-7|12).

Any opinions on this?
Thanks,
Angie
This is so easy. I sucked at math, and I found the answer to this.

Here goes: If ABC is who the hell cares? Math is useless anyways. Tell your math teacher to get a real job, teaching something that people will actually use in their lives.