linear factors of quadratic polynomials

• you can find solutions of quadratic equations using complex numbers
• e.g. factorise $x^2+2x+5$,
• solving $x^2+2x+5=0$ using QF gives
  • $-1\pm 2i$ (simplified)
• you can give it in the form $(x+p)(x+q)$ where $p$ and $q$ are the solutions to $x$
• $=(x+1-2i)(x+1+2i)$