Math problem.

Users who are viewing this thread

Hello guys and gals, objects and opportunitists.

I have a problem.

I am a alchoho-

I mean, I have a math problem.

I have two lines, one that can point in any direction except more than 90 degrees up. Pivoting from it's startpoint. Then I have the second starting and pivoting at the end of the first line. When the first line points at 180 degrees, ergo straight forwards, the second should point straight down. Like this:

math_part1.jpg


But let's say line 1 points slightly upwards, the result would be like this:

math_part2.jpg


However, in this case I don't want line 2 point straight down in this case, I want it to point to the same spot as before. Like this:

math_part3.jpg


What I need to figure out is the rate the second line needs to rotate at in order to always point at the same place, regardless of the direction of the first line.

I really don't even know where to start.

I don't have the specific lengths of the lines, but they're available when the formula is in use. So let's call them x and y for now.
 

G36E

Baron
I'm not free at the moment, so I can't write down the entire equation, but I'll give you a starting tip: write the x deviation of the start point of the second line from the end point in [line2 * sin(theta)].
 

xenoargh

Grandmaster Knight
Well, at least he's asking for something vaguely useful...

http://en.wikipedia.org/wiki/Perpendicular
 

mor2

Master Knight
@Graylord, it seem to me like a simple triangle problem...  just put the first drawing on top of the third and use what they taught you about angles.
 
Sorry, It's just years since I did proper math, and I can't remember squat.  :razz:
xenoargh said:
Well, at least he's asking for something vaguely useful...

http://en.wikipedia.org/wiki/Perpendicular

I am not sure what M is supposed to be.
Evilknightz said:
By the gods....

You mad brah?

mor2 said:
@Graylord, it seem to me like a simple triangle problem...  just put the first drawing on top of the third and use what they taught you about angles.

That WOULD be easy. If I had access to grid paper, a ruler and those degree measurers.  :sad:
 

mor2

Master Knight
I dont think you miss understood me, here:

2z6xqut.jpg

alpha being your new angle and beta (or initial value y minus beta being the second whatever you need, size or change)
you got 2 unkown's(alpha and beta), so you need 3 equations, just express them from the lower point angles (for each of the 3 rectangles, using only the values I put in) and you'll get your formula, its really a school grade exercise.
 
Top Bottom