/sci/ - Science & Math

All you can say if you just have hypotenuse of a right triangle is that the third vertex lies on a circle for which the hypotenuse is a diameter

>>4685495
cool. I really don't get why some people don't like maths, stuff like this is so interesting. Well, pure maths anyway. Mechanics can suck my balls.

>>4685495
An illustration of what this guy is saying

In general, you cannot tell what shape a triangle is by knowing just a length and an angle. You need at least one more piece of information.


Unless we are talking about integer only solutions.

>>4685521
But what about my equation? Unless my maths is wrong (can't be bothered to type out my whole working) it looks like it can be solved, I just don't know how.

>>4685488
>I can work out a way to solve a right angle triangle given only the hypotenuse.

This cannot be done, as there are an infinite amout of right traingles that can be made from the same hypotenuse. Make sense?

You need more constraints to actually get a unique right triangle.

>>4685521
though of interest that is not what i'm saying. your hypotenuse is a radius. learn to read

with a given hypothenuse there are as many right triangles as point in a circle, because a diameter of a circle and any point of this circle form a right triangle

>>4685528
the equation is wrong

cos(90 - x) = sin(x) by the way

you end up with sin(x) = sqrt(-1)

>>4685488
You can't solve it as there are no solutions (Well, no real solutions. Only imaginary)

pic related

>>4685488
However, I feel you should be rewarded for being inquisitive, thinking of your own mathematical problems and how to solve them.


So have a hot teen.

>>4685528
>equation
>doesn't even say what x represents

Your math is wrong, or it is redundant. If you did your math correctly, the only thing you will get is some tauntological unhelpful statement like, cos^2 + sin^2 = 1. Statements like that don't actually give any meaningfull insight to your problem.

What you are trying to do cannot be done, it is physically and mathematically impossible. Just look at the picture >>4685521.

All of those are right triganles with the same hypothenus, there are actually infinitely many of them. No amount of your shitty math is going to counter that argument.

However, if you specify more information you would be able to find a "unique" right trangl, out of the infinitly many.

>>4685565
you can get more than a redundancy, you van get the result in >>4685547 picture, known as Thales' theorem, expressed mathematically

>>4685565
Don't be a dickhead. At least he is interested.

But OP you equation doesn't really make sense. You have stated you only know 2 things, a length and an angle.

Seeing as we assume the angle is 90 degrees the variable x must be the length of the hypotenuse. So what it is doing as the variable in sin(x) and cos(x) I don't know...

>>4685565
you can get more than a tautology, you can get the result in >>4685547 picture, known as Thales' theorem, expressed mathematically

>>4685488
The equation you seek is just the pythagorean theorem:

h^2 = x^2 + y^2

h = your hypothenus
x = one side of triangle
y = other side of triangle

Given any value of h, you can find an infiite amount of (x,y) pairs that will work. Hence, there are an infinite amount of right triangles for a given hypothenus h.

Get it?

>>4685574
But Thales' theorem is a tantology in this context! It is a statement that is true for all the right-triganles with the hypothenus inscribed as the diameter in the circle.

It is the same shit as the pythagoran theorm. It is a tanutology because it is always true (in this given context). The only thing OP will stuble in his quest are tantologies like these.

It is impossible for him to find anything else but a tantologies (in this context) because he doesn't specifiy enough information for a unique right-triangle. Hence any mathematica equation he gets, must apply to all right triangles, hence it must be a tantology in that context.

>>4685605
all mathematical theorems are tautologies

>>4685605
What the FUCK are tantologies?

>>4685611

>>4685619
in logic, or rhetoric?

Fuck, just realised I never mentioned.

To clear up any confusion, x = one of the other angles. I tried again and ended up getting sin(x) = -90 , so I might have to give up and accept the logical explanation that there are infinite triangles. Still, gave me something to do that wasn't revising for Mechanics.

>>4685619
A tantology is a statement that is always true.
The pythagorean theorem is always true, so is Thales' theorem.

>>4685628
M1 tomorrow if Edexcel.

hope you can into vectors

>>4685631
So a tantology is basically the same as a tautology?
Also, lrn2sarcasm.

>>4685634
Yeah, C1 should be a doddle but moments fuck up my brain. Vectors at this level are piss-easy though, they're basically just another way of writing Cartesian co-ordinates.

>>4685628
You can't math for shit. Whatever you are doing is just fucking wrong.

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

What you should get is:
Sin(x) = X/H

Where x is the angle opposite the side of length X, and H is the hypotenuse.

>>4685639
try q 6

http://www.edexcel.com/migrationdocuments/QP%20GCE%20Curriculum%202000/January%202009/6677_01_que_20
090113.pdf

>>4685645
Obviously I know about SOHCAHTOA, I'm not a fucking retard, I was trying to do it with the cosine rule using substitutions to get just sin(x) to solve it. Clearly, it didn't work, but the fact remains that using the Law of Sines doesn't help when I'm trying to find it with only one side.

>>4685652
>>4685645
Using law of sines or cosine law is silly when you have a right triangle

one reduces to normal sin, the other to pythag

>>4685652
>I'm not a fucking retard

Your shitty thread would beg to differ

>>4685652
>solve a right angle triangle given only the hypotenuse

>I'm not a fucking retard


Yes, yes, you are. You are very fucking retarded. There is literaly a FUCKING PICTURE >>4685521
that shows the bullshit you are trying it fucking impossibe. Yet you continue to act like a little bitch and argue.

You are the defintion of retarded!

>>4685648
a) 153.43
b) show that question, but you use the fact that j = -2i
c) 1/4

checked the mark scheme, got it all right

>>4685488

>>4685676
what's wrong with solving for a locus rather than a point?

>>4685676
>>4685676
I'm not saying that it can be done, I was merely asking at the beginning. I'm not a fucking retard because I know what SOHCAHTOA is, and I would assume that everyone on /sci/ does.

>>4685686
>know what SOHCAHTOA is

>thought it might be possible to solve a right angle triangle given only the hypotenuse

You are seriously lacking some brain-cells.