Sin (x) in triagnle and in the unit circle

Whizzies · 2014-07-20 03:17:50

I am wondering you have the triangles with the definitions of sin (x), cos(x) and tan (x). You can calculate the angle with sin (x) = o /h, but I don't know what sin is. Sin (x) is just a function something that math people decided to do just that? Like Ln (x) ?

What is the difference between sin (x) with the triangles and the radian circle? I am trying to understand what sin (x) means in both of them, the basic figures come back in the Radian circle, but I don't see the connection!?

Sorry the question is some what vague I think, because I don't know how to ask something that I see but don't yet undestand wholly.

bobbym · 2014-07-20 03:24:47

There are other ways to define the sine function that have nothing to do with circles or triangles.

Whizzies · 2014-07-20 03:59:25

bobbym wrote:

There are other ways to define the sine function that have nothing to do with circles or triangles.

..... what does it all mean? What does sine mean?

bobbym · 2014-07-20 04:08:50

I think that it was originally defined in terms of a circle, that is why they call it a circular function. But it is also called a trigonometric function. The word "Trigonometry" is derived from two Greek words meaning measurement or solution of triangles.

Whizzies · 2014-07-20 04:15:19

bobbym wrote:

I think that it was originally defined in terms of a circle, that is why they call it a circular function. But it is also called a trigonometric function. The word "Trigonometry" is derived from two Greek words meaning measurement or solution of triangles.

So it is just like the circumference of a circle, when they tried to measure it up. They used squares all around I believe, and they came up with ''pi''. What is the relation between geometry and the unit circle?

What does sin( 1) = o/h = 0.01745... mean? in geometry?

Is there any relation between geometry and trigonometric?

bobbym · 2014-07-20 04:34:13

According to Wikipedia the sine function was defined in terms of the sides of a right triangle.

What does sin( 1) = o/h = 0.01745... mean? in geometry?

That shows the ratio between and angle of 1 degree and the opposite side and hypotenuse of a right triangle.

Whizzies · 2014-07-20 07:33:08

So it is a very very small rectangualr triangle?

bobbym · 2014-07-20 07:42:54

Nope, it is a right triangle. That means it has a 90 degree angle in it.

Whizzies · 2014-07-20 07:53:02

Sorry that is what I meant! I have a lot of questions hope you don't mind it.

I just found out that the Sine, Cosine, tangent in degrees can also be in radians (they both come on the unit circle).
If I say Sin (30) = 0.5; so: opposite = 1 and hypo = 2. This is an basic triangle just like the 45 degree and 60 degree. What if I take Sin (35), well o/h = 0.5737....

It is not possible to find out what O and H are right? because you have two variables.

bobbym · 2014-07-20 10:12:10

Hi;

Yes, you will need a little more information.

Math Is Fun Forum

#1 2014-07-20 03:17:50

Sin (x) in triagnle and in the unit circle

#2 2014-07-20 03:24:47

Re: Sin (x) in triagnle and in the unit circle

#3 2014-07-20 03:59:25

Re: Sin (x) in triagnle and in the unit circle

#4 2014-07-20 04:08:50

Re: Sin (x) in triagnle and in the unit circle

#5 2014-07-20 04:15:19

Re: Sin (x) in triagnle and in the unit circle

#6 2014-07-20 04:34:13

Re: Sin (x) in triagnle and in the unit circle

#7 2014-07-20 07:33:08

Re: Sin (x) in triagnle and in the unit circle

#8 2014-07-20 07:42:54

Re: Sin (x) in triagnle and in the unit circle

#9 2014-07-20 07:53:02

Re: Sin (x) in triagnle and in the unit circle

#10 2014-07-20 10:12:10

Re: Sin (x) in triagnle and in the unit circle

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