Math Is Fun Forum

carol_is_bored-a-man

Guest

Solve simultaneous equation using matrices

Hi, how do I solve this simultaneous equation using matrices.

x^2 + y^2 = 29
y - x = 3

MUST use a matrix method, but I missed all the lessons on how to do it please help. thank you.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solve simultaneous equation using matrices

Hi carol_is_bored-a-man;

You are posting the same questions under different names. I have already answered these, please read my responses before you post again.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

fred_watson

Guest

Re: Solve simultaneous equation using matrices

hi, I have this h/w assignment too. we have to solve it w/matrices. how to do it?

ps: i cant find your post bobbym

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solve simultaneous equation using matrices

Hi;

x^2 + y^2 = 29
y - x = 3

The only way I have ever seen involving matrices to solve equations like that utilizes the Jacobian in conjunction with newtons iteration. Strictly speaking you don't even require the Jacobian even there. I would not use any other method than simple substitution here. Like this:

y = 3 + x so substitute:

x^2 + (x+3)^2 = 29

x = -5, y = -2 and x = 2, y=5

So simple.

Please explain this to your teacher or have him/her come and explain it to me. Or copy the exact question from the text or direct me to the text that is demanding a matrix solution.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.