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If [x232y042z0]\begin{bmatrix} x - 2 & 3 & -2 \\ y & 0 & -4 \\ 2 & z & 0 \end{bmatrix} is a skew symmetric matrix, then the value of x+y+zx + y + z is

Solution

Correct Option: 4

For a skew symmetric matrix, two properties hold:

  • All diagonal elements are zero: aii=0a_{ii} = 0
  • Elements satisfy: aij=ajia_{ij} = -a_{ji}

Given matrix:

[x232y042z0]\begin{bmatrix} x - 2 & 3 & -2 \\ y & 0 & -4 \\ 2 & z & 0 \end{bmatrix}


The diagonal elements are (x2)(x-2), 00, and 00.

Since all diagonal elements must be zero:

x2=0x - 2 = 0

x=2x = 2


For elements at position (1,2) and (2,1):

Element at (1,2) =3= 3

Element at (2,1) =y= y

These must be negatives of each other:

3=y3 = -y

y=3y = -3


For elements at position (2,3) and (3,2):

Element at (2,3) =4= -4

Element at (3,2) =z= z

These must be negatives of each other:

4=z-4 = -z

z=4z = 4


x+y+z=2+(3)+4x + y + z = 2 + (-3) + 4

x+y+z=3x + y + z = 3

Therefore, the value of x+y+zx + y + z is 33.

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