Easy Practice — Set 2

Quick Recap — Quadratic Equations (Basics)

• For $ax^2+bx+c=0$: sum of roots $=-\tfrac ba$, product $=\tfrac ca$.
• Discriminant $D=b^2-4ac$: $D>0$ real distinct, $D=0$ real equal, $D<0$ complex conjugate.
• Roots: $x=\dfrac{-b\pm\sqrt{D}}{2a}$.
• A quadratic with roots $\alpha,\beta$ is $x^2-(\alpha+\beta)x+\alpha\beta=0$.