Answer :

To determine the absolute value (or magnitude) of a complex number given in the form \( a + bi \), where \( a \) and \( b \) are real numbers, we use the formula:

[tex]\[ \sqrt{a^2 + b^2} \][/tex]

For the complex number \( -4 - \sqrt{2} i \):

1. Identify the real part \( a \) and the imaginary part \( b \):
- The real part \( a = -4 \)
- The imaginary part \( b = -\sqrt{2} \)

2. Square the real and imaginary parts:
- \( (-4)^2 = 16 \)
- \( (-\sqrt{2})^2 = 2 \)

3. Sum the squares of the real and imaginary parts:
- \( 16 + 2 = 18 \)

4. Take the square root of the result:
- \( \sqrt{18} \)

To further simplify:

[tex]\[ \sqrt{18} = \sqrt{9 \times 2} = \sqrt{9} \times \sqrt{2} = 3\sqrt{2} \][/tex]

Thus, the absolute value of the complex number \( -4 - \sqrt{2} i \) is:

\[
3\sqrt{2}
\