Let me review the content of the image for accuracy. I will extract the details and verify the mathematical correctness.

Given Information from the Image:

1. The complex number $z = 8 + 6j$ is represented in the rectangular form.

2. $x = 8$, $y = 6$.

3. Calculation of the modulus $r = \sqrt{x^2 + y^2}$: $r = \sqrt{8^2 + 6^2} = \sqrt{64 + 36} = \sqrt{100} = 10$ Correct.

4. Calculation of the argument $\theta$ using ( \tan^{-1}\left(\frac