Finding the Determinant of a 2x2 Matrix

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Homework Help Overview

The problem involves finding the determinant of a 2x2 matrix B, given the condition that B applied to two different vectors results in the same output. Participants are exploring the implications of this condition on the determinant of the matrix.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between the matrix B and the vectors involved, questioning what it means for B to map two different vectors to the same result. There is an exploration of the implications of B being applied to the difference of the vectors.

Discussion Status

Some participants have suggested that the condition implies a specific property about the determinant of B, leading to a productive line of questioning about the nature of the matrix and its determinant. However, there is no explicit consensus on the final interpretation of the determinant.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may limit the information available for discussion. There are also indications of confusion regarding the relationship between the determinant and the properties of the matrix.

JFonseka
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Homework Statement


A 2 x 2 matrix B satisfies

B (3 1)[tex]^{T}[/tex] = B (5 2)[tex]^{T}[/tex]

What is det (B) ? Give a reason


Homework Equations



None really

The Attempt at a Solution



I really have no idea how to start solving this. Does it involve inversing?
 
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You are saying Bx=By. What's B(x-y)? Does that give you a hint?
 
So, It's B(-2 -1)[tex]^{T}[/tex]

I don't get it though. That doesn't look like a determinant.
 
It's also equal to zero since Bx=By. It's not a determinant. But Bz=0 where z is a nonzero vector. What can that tell you about the determinant of B?
 
That the determinant is 0 ?
 
Yessssss.
 
How do we know B(x) = 0?
 
Ah nvm I see.

Thanks for the help
 

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