Salam Academy
Paper 2 · Module

Algebra and functions

16 subtopics≈ 645 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
  6. Indices and surds

    amna^{\frac mn} means "take the nnth root, then raise to the power mm", and a−n=1ana^{-n}=\dfrac1{a^n}. Surds are roots left exact: simplify them by pulling out square factors, and remove them from denominators by multiplying by the conjugate.

    ≈ 30 min
  7. Polynomials: division, factor and remainder theorems

    Long division for polynomials, why the remainder on dividing by (x−a)(x-a) is just p(a)p(a), and how the factor theorem lets you factorise cubics and find unknown coefficients.

    ≈ 45 min
  8. Partial fractions

    Splitting a complicated fraction into simpler ones, which you need for integrating and for binomial expansions: the right form for each kind of denominator, and quick ways to find the constants.

    ≈ 45 min
  9. Modulus graphs and equations

    What ∣x∣|x| means, how to sketch y=∣ax+b∣y=|ax+b| by reflecting the negative part, and two reliable ways to solve modulus equations: squaring both sides, or splitting into cases and checking.

    ≈ 40 min
  10. Modulus inequalities

    Solving inequalities with moduli: the "between" and "outside" patterns, squaring when both sides are moduli, and using a sketch when a modulus is compared with a line.

    ≈ 40 min
  11. Curve sketching and transformations

    A factorised cubic crosses the xx-axis at each factor's root and touches it at a repeated root. Reciprocal graphs have asymptotes. Changes outside the bracket act vertically and do what you expect; changes inside act horizontally and do the opposite.

    ≈ 40 min
  12. Functions, domain and range

    What makes a rule a function, function notation, the largest possible domain, and how to find the range of linear and quadratic functions on any domain.

    ≈ 40 min
  13. Composite functions

    Applying one function after another: what fg(x)fg(x) means, finding and solving with composite expressions, and when a composite function exists.

    ≈ 35 min
  14. One-one and inverse functions

    Which functions can be undone, how to find f−1(x)f^{-1}(x), why the domain of the inverse is the range of the function, and how to invert a quadratic on a restricted domain.

    ≈ 45 min
  15. Graphs of a function and its inverse

    Why the graph of f−1f^{-1} is the reflection of ff in the line y=xy=x, how points, intercepts and asymptotes swap over, and where a function meets its own inverse.

    ≈ 30 min
  16. Transformations of graphs

    Translating, stretching and reflecting y=f(x)y=f(x): what each of f(x)+af(x)+a, f(x+a)f(x+a), af(x)af(x) and f(ax)f(ax) does, how to describe it in exam language, and how to combine transformations in the right order.

    ≈ 50 min