Math Is Fun Forum

Zirok

Member

Registered: 2010-06-06

Posts: 5

How to know a point's direction from a Orientation Point

Hi

I use the formula based on pythagorous therom (refer attachment) to calculate the distance from Orientation Point to 2 different points

  The problem to me is how to know the direction of the point. These points lie on opposite side (from orientation point) & how to know which one is on positive or negative side.
Thanks

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: How to know a point's direction from a Orientation Point

Hi Zirok;

I am not seeing your attachment.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Zirok

Member

Registered: 2010-06-06

Posts: 5

Re: How to know a point's direction from a Orientation Point

U can also see the the formula at -

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

See "Distance and angle" section.

Zirok

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: How to know a point's direction from a Orientation Point

Hi Zirok;

Have you tried subtracting the orientations x coordinate from the points x coordinate. If the ans is positve then the point is to the right. If negative the point is to the left.

This will work very well if what you are calling the orientation point is the origin ( 0 , 0 ). But that is not necessary.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Zirok

Member

Registered: 2010-06-06

Posts: 5

Re: How to know a point's direction from a Orientation Point

I am not able to attach anything over there.

Zirok

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: How to know a point's direction from a Orientation Point

Hi Zirok;

I prefer that you present your problem over here in the forum. I believe private email is both dangerous and against forum rules. I have removed your email address because in that form spammers and hackers can find it easily. I have done that for your own protection.

First question, did you find my idea satisfactory at least for you simple problem?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Zirok

Member

Registered: 2010-06-06

Posts: 5

Re: How to know a point's direction from a Orientation Point

Can you provide me aid on how to attach pictures so I can describe my point clearly.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: How to know a point's direction from a Orientation Point

Yes, what kind of file are you trying to attach?

I have modified you post #3 to show you how to put in an url. Just click edit at the bottom of the post to see what I have done.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Zirok

Member

Registered: 2010-06-06

Posts: 5

Re: How to know a point's direction from a Orientation Point

Jpeg file

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: How to know a point's direction from a Orientation Point

Hi Zirok;

Is the attachment on your computer or on the net? Please tell me and I will show you how to get it here.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.