Math Is Fun Forum

zegoat

Member

Registered: 2006-08-21

Posts: 7

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

Member

Registered: 2006-08-21

Posts: 8

Re: Engineering Mathematics Questions Help - - -complex Numbers

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

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

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

numen

Member

Registered: 2006-05-03

Posts: 115

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.

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Bang postponed. Not big enough. Reboot.

stacey

Member

Registered: 2006-08-21

Posts: 8

Re: Engineering Mathematics Questions Help - - -complex Numbers

can no one answer these questions?

stacey

Member

Registered: 2006-08-21

Posts: 8

Re: Engineering Mathematics Questions Help - - -complex Numbers

sorry i meant on my post lol