Can Geometry Help Solve This Vector Problem?

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Homework Statement



(E) is a group of points M from a level/plane

MA^{2}-MB^{2}=-4 And I is the center of [AB]

Homework Equations



show that IM*AB=-2 ( IM and AB have arrows on top)

The Attempt at a Solution



Well i split MA^{2}-MB^{2}=(MA-MB)(MA+MB)

then i got : MA^{2}-MB^{2}=BA*(MA+MB)

and i don't know where to go on from there any help?
 
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mtayab1994 said:

Homework Statement



(E) is a group of points M from a level/plane

MA^{2}+MB^{2}=-4 And I is the center of [AB]
This doesn't make any sense to me.

What is A? What is B? Is AB the line segment from point A to point B?
mtayab1994 said:

Homework Equations



show that IM*AB=-2 ( IM and AB have arrows on top)

The Attempt at a Solution



Well i split MA^{2}-MB^{2}=(MA-MB)(MA+MB)

then i got : MA^{2}-MB^{2}=BA*(MA+MB)

and i don't know where to go on from there any help?
 
Mark44 said:
This doesn't make any sense to me.

What is A? What is B? Is AB the line segment from point A to point B?

My fault AB is a line segment and I is the center of it.
 
mtayab1994 said:

Homework Statement



(E) is a group of points M from a level/plane

MA^{2}+MB^{2}=-4 And I is the center of [AB]
...
I think this is impossible! → MA^{2}+MB^{2}=-4

Do you mean? → MA^{2}-MB^{2}=-4
 
SammyS said:
I think this is impossible! → MA^{2}+MB^{2}=-4

Do you mean? → MA^{2}-MB^{2}=-4


Yea sorry my fault that was a typo its MA^2-MB^2=-4
 
Any ideas?
 
What does this mean?
mtayab1994 said:
show that IM*AB=-2 ( IM and AB have arrows on top)
Does * represent the dot product?
 
Mark44 said:
What does this mean?

Does * represent the dot product?

Yes.
 
mtayab1994 said:

Homework Statement



(E) is a group of points M from a level/plane

MA^{2}-MB^{2}=-4 And I is the center of [AB]

Homework Equations



show that IM*AB=-2 ( IM and AB have arrows on top)

The Attempt at a Solution



Well i split MA^{2}-MB^{2}=(MA-MB)(MA+MB)

then i got : MA^{2}-MB^{2}=BA*(MA+MB)

and i don't know where to go on from there any help?

mtayab1994 said:
My fault AB is a line segment and I is the center of it.
Since "IM and AB have arrows on top", and "AB is a line segment", I take it that these are all vectors and, for example, \vec{MB} is a vector from point M to point B.

If that's the case, then notice that \vec{MA}=\vec{MI}+\vec{IA}\,. Do similar for \vec{MB}

Notice that\vec{IB}=-\vec{IA}\,.

Now look at \vec{MA}+\vec{MB} again.
 
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