Porisma

Check the assumed knowledge

Use this checklist to identify what to revise. The source groups the skills as A1–A4, B5–B6 and C7.

A1: Quadratics, equations and inequalities

  • Complete the square to find a quadratic’s maximum or minimum.
  • Distinguish two real roots, two equal real roots and no real roots.
  • Determine when ax2+bx+cax^2+bx+c is always positive or always negative.
  • Solve two simultaneous equations by substitution when one equation is linear.

A2: Surds

  • Perform all four operations on surds, including rationalising denominators.
  • Solve equations involving surds.

A3: Polynomials and partial fractions

  • Multiply and divide polynomials; apply the remainder and factor theorems.
  • Resolve partial fractions with denominators no more complicated than (ax+b)(cx+d)(ax+b)(cx+d), (ax+b)(cx+d)2(ax+b)(cx+d)^2 and (ax+b)(x2+c2)(ax+b)(x^2+c^2).

A4: Exponentials and logarithms

  • Work with axa^x, exe^x, log⁡ax\log_a x, ln⁡x\ln x and their graphs.
  • Apply logarithm laws, the equivalence y=ax  ⟺  x=log⁡ayy=a^x\iff x=\log_a y, and change of base.
  • Simplify expressions and solve simple exponential and logarithmic equations.

For real logarithms, the base must satisfy a>0a>0, a≠1a\ne1 and the argument must be positive; these domains make the source equivalence meaningful.

B5: Coordinate geometry

Recognise the circle in either form (x−a)2+(y−b)2=r2(x-a)^2+(y-b)^2=r^2 or x2+y2+2gx+2fy+c=0x^2+y^2+2gx+2fy+c=0, with the appropriate radius condition for a real circle.

B6: Trigonometry

  • Use all six trigonometric functions and the principal values of inverse sine, cosine and tangent.
  • Solve trigonometric equations and use identities from the source’s List of Formulae reference.
  • Express acos⁡θ+bsin⁡θa\cos\theta+b\sin\theta as rsin⁡(θ±α)r\sin(\theta\pm\alpha) or rcos⁡(θ±α)r\cos(\theta\pm\alpha).

C7: Differentiation and integration

  • Interpret a derivative as a tangent gradient and as a rate of change.
  • Differentiate xnx^n for rational nn, sin⁡x\sin x, cos⁡x\cos x, tan⁡x\tan x, exe^x, ln⁡x\ln x, and constant multiples, sums and differences.
  • Apply chain, product and quotient rules.
  • Study increasing/decreasing functions and stationary points, including maxima, minima and stationary points of inflexion.
  • Use the second derivative test, connected rates and optimisation.
  • Treat integration as reverse differentiation.
  • Integrate xnx^n for rational nn, exe^x, sin⁡x\sin x, cos⁡x\cos x, sec⁡2x\sec^2x, and their constant multiples, sums and differences.
  • Integrate (ax+b)n(ax+b)^n, sin⁡(ax+b)\sin(ax+b), cos⁡(ax+b)\cos(ax+b) and eax+be^{ax+b}.

Work on real intervals where the functions and rules are defined. In particular, n=−1n=-1 uses a logarithmic antiderivative rather than the ordinary power rule; linear-inner substitutions need a≠0a\ne0, or separate treatment of a constant integrand. A zero second derivative alone does not establish a turning point or inflexion.

Revise these methods in the readiness chapter.

CJC · 2025 Introduction · PDF 2 · printed ii