Solving Equations with Complex Roots (Edexcel A-Level Further Mathematics): Flashcards

$\Delta = b^2 - 4ac$

Real and distinct

Real and equal

Complex conjugates

$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

Conjugate pairs

$-1$

$a - bi$

$x = a \pm bi$

$x = -2 \pm i$