Thanks should be correct despite the weird answer...i got the same answer too with a diff method

z² = 96 - 168i

Express in exponential form.

r = √(96² + 168²)
r = √37440

tan θ = -168/96 = -7/4
θ = tan-¹ (-7/4) ≈ -1.052 rad

z² lies in the third quadrant so arg (z²) = -1.052 rad

so z² = √37440 e^(-1.052i)

= √37440 e^(-1.052 + 2kπ)i, k ∈ Z


z = √(√37440 e^(-1.052+ 2kπ)i)

z = ⁴√37440 e^((-1.052 + 2kπ)i/2) , k = 0, 1

z = ⁴√37440 e^(-1.052i/2) , ⁴√37440 e^((-1.052 + 2π)i/2)


z ≈ -6.98402i + 12.0299, 6.98402i -12.0299