Step-by-step explanation:
You are close. When calculating the radius and angle, you use the magnitudes of the real and imaginary terms. In other words, you leave out the i in the calculation.
r = √((-8)² + (√3)²)
r = √(64 + 3)
r = √67
θ = π + atan((√3) / (-8))
θ ≈ 2.928
