Solve by factorising and by formula, read the nature of the roots off the discriminant, and work through quadratic inequalities with confidence.
4 free units in this chapter
Grade 11 completes your quadratic toolkit: when factorising fails, the quadratic formula always works.
About 3 minThe discriminant Δ = b² − 4ac tells you about the roots without solving the equation.
About 3 minA quadratic inequality asks where a parabola is above or below zero, so the answer is a set of intervals.
About 3 minBeyond finding roots, Grade 11 asks you to reason about them algebraically.
About 3 min