Math SL Type I HELP -MATRICES

[ibastudent]

Hi there's one of the questions in my type I task that I don't understand. It says "M= a+b a-b / a-b a+b (2 by 2 MATRIX)

show that M= A+B, and that M^2 = A^2 +b^2".

First of all, how can M^2 = A^2 +b^2 and not (A+B)^2????

Help needed, Thanks!

Edited March 15, 2009 by ibastudent

[Sandwich]

I don't know how much help people are allowed to give on here, but if I were you, I would suggest re-checking the following statement:

First of all, how can M^2 = A^2 +b^2 and not (A+B)^2????

Put in real values for a, b, and n and try out what you just stated. You may find an error in your reckoning (:

[ibastudent]

I don't know how much help people are allowed to give on here, but if I were you, I would suggest re-checking the following statement:

Put in real values for a, b, and n and try out what you just stated. You may find an error in your reckoning (:

The problem is, I've been trying hard to prove that M^2 = A^2+B^2 and it just doesn't work! I thought since M=A+B, won't M^2=(A+B)^2? and not "M^2=A^2+B^2"?

I know what I'm saying is confusing, but I don't know how else to say it.

Hope you can help though, thanks!

Edited March 15, 2009 by ibastudent

[Sandwich]

I thought since M=A+B, won't M^2=(A+B)^2? and not "M^2=A^2+B^2"

Again, I suggest you try this out with real values! Unless I got mine very wrong, you should find that both of these are the same (i.e. A^2 + B^2 = (A+B)^2)

[deissi]

There already exists a topic on this portfolio, I suggest you ask there should you have any further questions.