Salam Academy
Paper 1 · Module

Quadratics

5 subtopics≈ 205 min in total
  1. Completing the square and the vertex

    Rewrite ax2+bx+cax^2+bx+c as a(x+p)2+qa(x+p)^2+q, read off the vertex, line of symmetry and least or greatest value, and use it to sketch parabolas and solve real problems about maximum height or area.

    ≈ 45 min
  2. Solving quadratic equations

    Three ways to solve ax2+bx+c=0ax^2+bx+c=0 (factorising, completing the square and the formula), choosing the quickest, giving exact answers, and spotting quadratics in disguise such as x4−5x2+4=0x^4-5x^2+4=0.

    ≈ 45 min
  3. The discriminant and the nature of roots

    How b2−4acb^2-4ac tells you whether a quadratic has two, one or no real roots without solving it, how to find unknown constants from that, and how to show an expression is always positive.

    ≈ 40 min
  4. Linear and quadratic inequalities

    Solve linear inequalities, then quadratic ones using critical values and a sketch, write the answer correctly (and, or, set notation), and combine two conditions.

    ≈ 35 min
  5. Simultaneous equations and lines meeting curves

    Solve one linear and one quadratic equation together by substitution, find the points where a line meets a curve, and use the discriminant to decide whether a line crosses, touches or misses a curve.

    ≈ 40 min