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#1 2005-07-26 01:09:02

GurraTedden
Member
Registered: 2005-07-20
Posts: 19

Trigonometric, is it possible?

Hi, check this out:

http://engman.bravehost.com/mechanics/side.JPG

I've been sitting with it for 2 hours now, it just makes me crazy. I mean, it is
a possibility that the mechanical problem that this trig. is derived from is ment
to be solved in an other way, but i wouldn't bet my money on that.

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#2 2005-07-26 01:17:51

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Trigonometric, is it possible?

I'm probably reading your drawing wrong, but couldn't you use Pythagoras?

If so, x²=0.3²-0.2²
x²=0.05
x=√0.05≈0.223


Why did the vector cross the road?
It wanted to be normal.

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#3 2005-07-26 01:44:18

GurraTedden
Member
Registered: 2005-07-20
Posts: 19

Re: Trigonometric, is it possible?

That's the problem, man! The answer should be 0.75, but I can't see it. I need to know if I can solve it,
or if I have to find another way of attacking the original problem. I would also like to read it like you did,
but unfortunately I have drawn it correct. The side 0.3 is not the hyp. of the little triangle. I have gone
forth and back on if there is some kind of connection between the ratios, or (what you call the relationship
between the sides that's not the hyp.)

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#4 2005-07-26 02:06:52

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Trigonometric, is it possible?

Well, if you don't have the hypotenuse, then it can't be solved as it is, because to use trigonometry you need 3 pieces of information and you've only got 1 side and 1 angle.
So, yes, you need to attack it another way. If you're still stuck then post the whole problem on here.


Why did the vector cross the road?
It wanted to be normal.

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#5 2005-07-26 03:19:34

GurraTedden
Member
Registered: 2005-07-20
Posts: 19

Re: Trigonometric, is it possible?

But it's a mechanics problem.

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#6 2005-07-26 09:40:37

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,555

Re: Trigonometric, is it possible?

The bigger triangle is a 3:4:5 triangle, but it could be sitting at any angle relative to the (0.2 and x) triangle, so x could be large or small.

Is it part of a wider problem? Perhaps there is a clue there.


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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