matrix equations

[opaque pecan]

Part a is fine, but I don’t get part b,
You have to explain why it’s impossible to solve the equation BX = C? any help appreciated. Thanks

I’m assuming it’s something to do with B having no inverse, but idk what that means 🤨

Ik what inverses are but idk how to deal with a question saying a matrix has no inverse

[stray gulch]

ur correct, if the determinant of a matrix is 0, then the matrix is singular and has no inverse

so u just need to work out the determinant of the matrix

[frank gyro]

🤔

[lapis hull]

so if u solve BX = C, the way you would solve for X is by doing B^-1BX = B^-1C

whcih would then lead to X = B^-1C

if B^-1 does not exist, then you cannot solve for X

so just write it like that

then prove that the inverse does not exist

[opaque pecan]

How do you do that

[lapis hull]

well the way you find the inverse is by doing 1/detM(changed matrix)

so since detM is 0

1/detM is undefined

so the inverse is undefined

[frank gyro]

Cold

[sharp swan]

With these types of questions, you should try giving it a go and see what happens when you try to solve it. Like others above have explained it's because matrix B doesn't have an inverse

[burnt fable]

What exam board, as that doesnt look familiar to em

[opaque pecan]

Ccea (Northern Ireland)

[burnt fable]

ok

I do Edexcel

so never seen that before

[opaque pecan]

Yeah I don’t think there’s many if even any northern Irish ppl in here

[frank gyro]

There are questions like that in edexcel

There was one on an AS past paper to do with the matrices not being conformable

[burnt fable]

what chapter would I find that in?