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•  » Engineering Mathematics Questions Help - - -complex Numbers

## #1 2006-08-22 20:04:02

zegoat
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### Engineering Mathematics Questions Help - - -complex Numbers

Hi

QUESTION 1

A
Can anyone answer these questions? And show working out...

If
A = (2  -1  0       ,  B = (3      ,      C = (1  6  5
-1   1  6)                 2                    3   4  1)
4)

Find, where possible: 3A-B, AB and CA

B

Let
E= (2  5     and   F = (4  -5
-3  1)                   3   k)

For what values of k, if any, does EF=FE

Find the inverse of E and hence solve:

2x + 5y = -4
-3x + y = 7

C

Let M =  (0  1  2
1  0  3
4 -3  8)

Find the determinant and inverse of M

hence solve the system:

y + 2z = -11
x + 3z = -20
4y - 3y + 8z = -61

stacey
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## #3 2006-08-23 03:18:57

luca-deltodesco
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### Re: Engineering Mathematics Questions Help - - -complex Numbers

is addition and subtraction allowed for matrices with different dimensions? i dont think so

CA is not allowed, the number of collumns of C is not equal to the number of rows in A, so multiplication doesnt work

B)

the rest i dont know

The Beginning Of All Things To End.
The End Of All Things To Come.

## #4 2006-08-23 04:18:32

numen
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### Re: Engineering Mathematics Questions Help - - -complex Numbers

C)

Maybe I'll do the inverse later, god I'm hungry But basically, MX=Y, so the inverse is what you'll find in front of Y in X=M-¹Y.

Bang postponed. Not big enough. Reboot.

## #5 2006-08-23 20:28:07

stacey
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### Re: Engineering Mathematics Questions Help - - -complex Numbers

can no one answer these questions?

## #6 2006-08-23 20:29:07

stacey
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### Re: Engineering Mathematics Questions Help - - -complex Numbers

sorry i meant on my post lol

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