classwizz help

I am trying to learn further maths A level. I'm a mature person not in school so have no peers or teachers to ask. I'm currently trying to get to grips with the chapter on Matrices. I can use the classwizz for several things but cannot find how to use it get the Matrix of Cofactors nor the transposed version. I particularly want to use it for a non-singular matrix.

Any ideas anyone?

Thanks

Reply 1

Lancaster Student Ambassador

Official Rep

15

Original post by maggiehodgson

I am trying to learn further maths A level. I'm a mature person not in school so have no peers or teachers to ask. I'm currently trying to get to grips with the chapter on Matrices. I can use the classwizz for several things but cannot find how to use it get the Matrix of Cofactors nor the transposed version. I particularly want to use it for a non-singular matrix.

Any ideas anyone?

Thanks

Hi @maggiehodgson,

It's SO COOL to hear that you're taking the initiative to learn further maths A level! I did GCSE Further maths so can only do basic matrices (without a calculator) unfortunately :frown:

However, you should definitely try to use either YouTube or Chat GPT to help.

Shaheer (Lancaster Student Ambassador)

Reply 2

Muttley79

20

Original post by maggiehodgson

I am trying to learn further maths A level. I'm a mature person not in school so have no peers or teachers to ask. I'm currently trying to get to grips with the chapter on Matrices. I can use the classwizz for several things but cannot find how to use it get the Matrix of Cofactors nor the transposed version. I particularly want to use it for a non-singular matrix.

Any ideas anyone?

Thanks

Useful website: https://www.drfrostmaths.com/courses.php?coid=352

Classwiz https://www.drfrostmaths.com/downloadables.php?rid=262

Reply 3

RichE

15

Original post by maggiehodgson

I am trying to learn further maths A level. I'm a mature person not in school so have no peers or teachers to ask. I'm currently trying to get to grips with the chapter on Matrices. I can use the classwizz for several things but cannot find how to use it get the Matrix of Cofactors nor the transposed version. I particularly want to use it for a non-singular matrix.

Any ideas anyone?

Thanks

Will classwizz work out determinants and inverses. If so, then the matrix of cofactors of an invertible matrix A equals

det(A) (A^T)^(-1)

where ^T denotes transpose and ^(-1) denotes inverse.

EDIT: never used classwizz but on the Mode 4 slide at

Classwiz https://www.drfrostmaths.com/downloadables.php?rid=262

there seems to be the operations you need.

(edited 9 months ago)

Reply 4

Ignorabimus

9

Original post by maggiehodgson

I am trying to learn further maths A level. I'm a mature person not in school so have no peers or teachers to ask. I'm currently trying to get to grips with the chapter on Matrices. I can use the classwizz for several things but cannot find how to use it get the Matrix of Cofactors nor the transposed version. I particularly want to use it for a non-singular matrix.

Any ideas anyone?

Thanks

From memory, classwizz or any calculator cannot give you the matrix of cofactors, since that's a step in finding the inverse of something like a 3x3. Similarly transposing a matrix, I have no idea how that can be done on a calculator, but it's just taking the rows in descending order and writing them out as columns in the same order, or taking the columns and writing them as the rows. The calculator may help with finding the cofactor matrix since you can calculate the determinants of 2x2, but usually, it's quicker in the head than to use a calculator for that, more practice helps.

Reply 5

maggiehodgson

OP

14

Original post by Muttley79

Useful website: https://www.drfrostmaths.com/courses.php?coid=352

Classwiz https://www.drfrostmaths.com/downloadables.php?rid=262

Thanks

I'll try that today and if I have any luck I'll let you know.

Reply 6

maggiehodgson

OP

14

Original post by RichE

Will classwizz work out determinants and inverses. If so, then the matrix of cofactors of an invertible matrix A equals

det(A) (A^T)^(-1)

where ^T denotes transpose and ^(-1) denotes inverse.

EDIT: never used classwizz but on the Mode 4 slide at

Classwiz https://www.drfrostmaths.com/downloadables.php?rid=262

there seems to be the operations you need.

Hi

Yes, clazzwizz can work out determinants and inverses. It won't do inverses of a singular matrix though. I've seen a solution to finding the geometric configuration of planes that requires the finding of the co-factors. I can do it by head but it's a bit tedious so I was hoping for a calculator method, Thanks for your input though I'm sure what you have told me will be put to use.

Reply 7

maggiehodgson

OP

14

Original post by RichE

Will classwizz work out determinants and inverses. If so, then the matrix of cofactors of an invertible matrix A equals

det(A) (A^T)^(-1)

where ^T denotes transpose and ^(-1) denotes inverse.

EDIT: never used classwizz but on the Mode 4 slide at

Classwiz https://www.drfrostmaths.com/downloadables.php?rid=262

there seems to be the operations you need.

H

I've just had a wizz (haha) through the ppt. I've learnt a couple of very interesting things like the CALC button and the approx= button. Sadly there is no info on cofactors. Also, you cant go A^-1 on a singular matrix. It was worth reading though so thanks again.

Reply 8

RichE

15

Original post by maggiehodgson

H

I've just had a wizz (haha) through the ppt. I've learnt a couple of very interesting things like the CALC button and the approx= button. Sadly there is no info on cofactors. Also, you cant go A^-1 on a singular matrix. It was worth reading though so thanks again.