Question

What are the solutions of the equation (z^2)+9=0

Answer 1

z = ± 3i

Explanation:

note that
`√(-1)` = i

Given

z² + 9 = 0 ( subtract 9 from both sides )

z² = - 9 ( take the square root of both sides )

z = ±
`√(-9)` = ±
`√(9(-1))` = ±
`√(9)` ×
`√(-1)` = ± 3i