Answer :

Certainly! To find the value of the expression [tex]\( x^2 - y^2 - z^2 \)[/tex] given the values [tex]\( x = 1 \)[/tex], [tex]\( y = 2 \)[/tex], and [tex]\( z = 3 \)[/tex], follow these steps:

1. Substitute the values into the expression.

[tex]\[ x = 1, \quad y = 2, \quad z = 3 \][/tex]

2. Calculate [tex]\( x^2 \)[/tex]:

[tex]\[ x^2 = 1^2 = 1 \][/tex]

3. Calculate [tex]\( y^2 \)[/tex]:

[tex]\[ y^2 = 2^2 = 4 \][/tex]

4. Calculate [tex]\( z^2 \)[/tex]:

[tex]\[ z^2 = 3^2 = 9 \][/tex]

5. Substitute these values back into the expression [tex]\( x^2 - y^2 - z^2 \)[/tex]:

[tex]\[ x^2 - y^2 - z^2 = 1 - 4 - 9 \][/tex]

6. Perform the subtraction:

[tex]\[ 1 - 4 - 9 = -3 - 9 = -12 \][/tex]

Therefore, the value of the expression [tex]\( x^2 - y^2 - z^2 \)[/tex] when [tex]\( x = 1 \)[/tex], [tex]\( y = 2 \)[/tex], and [tex]\( z = 3 \)[/tex] is [tex]\(-12\)[/tex].