Question

Solve this equation over the set of complex numbers.
x2=
–
25
x=
or x=

Answer 1

Solve x^2 = −25.

x^2 + 25 = 0 ⇒ x^2 = −25 ⇒ x = ±√(−25) = ±5i.

So x = 5i or x = −5i.