Math Is Fun Forum

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

You are not logged in.

#726 Re: Help Me ! » Translate local vector to world vector » 2014-06-23 11:43:27

Ok, so, with the euler angles you supply the position and orientation of the ship and you need to calculate the velocity vector's end point. Git it, I think. I will have to look into the Euler angles a bit more though. That seems to be the toughest part.

#727 Re: Help Me ! » the bird flies,and flies,and flies again. » 2014-06-23 11:38:40

Yes, if L' (length of the bird) is 0, it is an infinite number of times. If not, then it gets a bit more complicated. All I can say for that case is that after t=(L-L')/(2V) time, L' starts monotonically decreasing. smile

#728 Re: Help Me ! » Why is there an associative law? » 2014-06-23 11:34:11

Hi Isomorph

What does that have to do with why there is an associative law?

#729 Re: Help Me ! » Why is there an associative law? » 2014-06-22 09:07:15

It needs to be a formal rule because there non-associative operations.

The commutative law does not allow omitting parentheses.

#730 Re: This is Cool » Tracing a Function » 2014-06-22 06:54:25

Yes, sorry.

I think they can be drawn.

#731 Re: This is Cool » Tracing a Function » 2014-06-22 06:23:59

That one isn't solvable, I'd say. At least in terms of elementary functions.

What I am doing is just taking


and substituting it into the given equation and solving for y.

#733 Re: This is Cool » Tracing a Function » 2014-06-22 05:55:21

Well, an ellipse isn't exactly a function, but, it can be done, I'd say. It would be very complicated in some cases.

#734 Re: This is Cool » Tracing a Function » 2014-06-22 05:41:58

Hi Maburo

The equation you are looking for is:


where a and b come from the equation of the ellipse:

#735 Re: Help Me ! » 64 pawns » 2014-06-22 02:46:46

Well, as I said, I don't think it is necessary to fill up the whole table. It is enough to see in how many ways the table below can be filled up with k white and 32-k black pawns.

EEJ3WQA.png

#736 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 08:50:29

Well, I think I need enlightenment myself. Your best bet is to wait for Bob, but I will try doing it in the mean time.

#737 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 08:13:38

Actually, I just looked at the info on wikipedia a bit. You are right, you don't need 4 angles. Three is enough.

#738 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 07:39:08

No, no. You will need angles gamma and delta for the rotation of the ship.

#740 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 07:32:55

Okay, I think I see the problem here. But, if I'm not mistaken, and I might be, you would need two more angles for the rotation of the rocket.

#741 Re: Help Me ! » bases » 2014-06-21 07:12:47

Well, I do not see why it is easy. I just know it was easy for me.

#742 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 07:09:00

Well, he clarifies that "radius" refers to the velocity vector.

Also, I think you missed the word play in the last sentence of my last post.

#743 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 06:45:58

Those coordinates make sense because that's the way the vector can be decomposed in 3D.

I don't think it's around a world axis. It seems to be a rotation of the ship, but neither affect any coordinates, so I'm not sure what that's about.

Yes, I did miss the pun. I quite like it, unlike most people. smile

#744 Re: Help Me ! » bases » 2014-06-21 06:29:43

Ah, okay. Post #67 is confusing.

#745 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 06:23:14

Hi Bob

Are you sure it is moving on the surface of the sphere?

I am also stuck with the point of view. The only reference frame that makes sense is the world, but it doesn't seem to be so... dunno

#746 Re: Help Me ! » bases » 2014-06-21 06:14:41

I did not understand what you meant. You got the same answer?

#748 Re: Help Me ! » Translate local vector to world vector » 2014-06-21 06:10:23

Hi DeadBeef

I'm not sure what you are asking. What I understood is that you are trying to get the x, y and z component of the velocity vector. Is that correct?

#749 Re: Help Me ! » bases » 2014-06-21 06:02:43

I already posted my answer in post #54.

#750 Re: Help Me ! » bases » 2014-06-21 05:41:56

Are you getting what I got?

Board footer

Powered by FluxBB