Introduction to the Cosmic Background Radiation (‘CBR’) that goes with the Big Bang. Briefly summarising the Big Bang and the search for & confirmation of CBR. 2 sides.

IGCSE Atomic Structure, animated powerpoint. Electrons, protons & neutrons. Introducing Isotopes, Atomic weight, the Billiard Ball model, the Plum pudding model, the Gold Foil experiments, the Nuclear model, the Electron Shell model & electron configuration. 22 slides.

Electrostatics, voltage and current, dangers and protection for devices and humans, measuring voltage, current, power and energy, series and parallel circuit resistance, introducing variable resistors, NTC thermistors, LDRs, diodes, capacitors, relays, transformers, rectifiers and inverters.

Turning the general circle equation into the standard equation by completing the square. From 3 circumference points to the circle equation in < 2 mins. The 3 points can be translated by the negative of the position vector of any one of the points to make the circumference pass through the origin, thereby enabling the general equation, x^2 + y^2 = 2xh + 2yk, to be used on the other two points to reveal the centre coordinates, (h, k), of the shifted circle. Pythagoras’ rule on the centre coordinates will reveal the radius and these centre coordinates should be translated back by the original position vector to reveal the centre of the original circle.

Parallelogram area in under a minute. Using the position vectors of 2 corners from another corner, (ai, bj) & (ci, dj), area = |ad - bc|. Geometric and algebraic proofs are included.

IGCSE Introduction to Calculus animated powerpoint. The gradient ratio as rise-over-run and the limit for a tangent to a curve as the ‘derivative’. Examples of the limit/derivative for straight line, a parabola and a cubic. The use of the derivative to find ‘turning points’, and the distinction between a local maximum and a local minimum. 15 slides.