grade 11 · A2-007

Find complex quadratic roots

Interpret a negative radicand with i and keep both square-root branches.

Learn togetherFresh problem · seed 304822811

Solve \(x^2+4=0\).

Let's work it out together.

Work through one checkpoint at a time. Your answer area opens after the reasoning.

Checkpoint 1

Isolate x-squared first.
Checkpoint 2

Write \(\sqrt{-1}=i\).
Checkpoint 3

A nonzero square has both a positive and negative square root.

\(x=\pm 2i\)\(x=\pm 2\)\(x=2i\)\(x=\pm 4i\)