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- Thread starter zuby
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You need to set up an augmented matrix with the identity matrix next to it, then go through a series of row operations until the matrix on the left becomes the identity matrix...Hi,

Can anyone help me to inverse the below matrix by row reduction method.

I know determinant method but I don't know row reduction method please help me.

4 5

-2 6

thanks.

- Feb 21, 2013

- 739

Hello,Hi,

Can anyone help me to inverse the below matrix by row reduction method.

I know determinant method but I don't know row reduction method please help me.

4 5

-2 6

thanks.

here you got some exemple as you can see you can do it in Two way! (Look at second exemple) Mathwords: Inverse of a Matrix

Remember to always check your soultion! When you find your inverse and multiply by the non inverse Then you should get unit matrix! ( the one with 1 on diagonal and zero at rest!) With other words

\(\displaystyle AA^{-1}=I\) some use I or E for unit matrix but that I is unit matrix!

Regards,

\(\displaystyle |\pi\rangle\)

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- #4

Thanks for quick response.Hello,

here you got some exemple as you can see you can do it in Two way! (Look at second exemple) Mathwords: Inverse of a Matrix

Remember to always check your soultion! When you find your inverse and multiply by the non inverse Then you should get unit matrix! ( the one with 1 on diagonal and zero at rest!) With other words

\(\displaystyle AA^{-1}=I\) some use I or E for unit matrix but that I is unit matrix!

Regards,

\(\displaystyle |\pi\rangle\)

I checked the site that you sent and understood row reduction method but that was easy. When I calculate the matrix values that I posted in previous. it will not give the same result that I have in my book here is my above matrix solution from my book. there is confusion below the image at red circled area how (17/2) is calculated by the book author.

Please help me thanks

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- #5

- Mar 5, 2012

- 9,790

Where is the confusion?

The 17/2 is calculated from:

$$R_2'=R_2+2R_1'$$

$$6 + 2 \cdot \frac 5 4 = \frac{12}{2} + \frac 5 2 = \frac{17}{2}$$

- Feb 21, 2013

- 739

what they did is that they did multiply 2 to R1 and add to R2. It is exactly what they mean with \(\displaystyle R_2'=R_2+2R_1'\)Thanks for quick response.

I checked the site that you sent and understood row reduction method but that was easy. When I calculate the matrix values that I posted in previous. it will not give the same result that I have in my book here is my above matrix solution from my book. there is confusion below the image at red circled area how (17/2) is calculated by the book author.

View attachment 1577

Please help me thanks

\(\displaystyle \frac{2*5}{4}+6=\frac{17}{2}\)

does that make it clear for you?

Edit: I like Serena was faster

Regards,

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- #7

When I calculate it says 16 over 4. Where am I making mistake?what they did is that they did multiply 2 to R1 and add to R2. It is exactly what they mean with \(\displaystyle R_2'=R_2+2R_1'\)

\(\displaystyle \frac{2*5}{4}+6=\frac{17}{2}\)

does that make it clear for you?

Edit: I like Serena was faster

Regards,

\(\displaystyle \frac{2*5}{4}+6\)

\(\displaystyle \frac{10}{4}+\frac{6}{1}=\frac{10}{4}+\frac{6}{4}=\frac{16}{4}\)

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- #8

- Mar 5, 2012

- 9,790

$$\frac{6}{1} \ne \frac{6}{4}$$When I calculate it says 16 over 4. Where am I making mistake?

\(\displaystyle \frac{2*5}{4}+6\)

\(\displaystyle \frac{10}{4}+\frac{6}{1}=\frac{10}{4}+\frac{6}{4}=\frac{16}{4}\)

This should be:

$$\frac{6}{1} = \frac{24}{4}$$

- Thread starter
- #9

Oh I was not multiplying 4 by numerator 6.$$\frac{6}{1} \ne \frac{6}{4}$$

This should be:

$$\frac{6}{1} = \frac{24}{4}$$

Under of thanks.