1. Simplifying expressions
Simplify algebraic expressions by combining like terms and using distributive property.
Example: Simplify $3x + 5x - 2 = (3+5)x - 2 = 8x - 2$
2. Rearranging formulae
Isolate the desired variable by performing inverse operations on both sides.
Example: Rearrange $A = 2l + 2w$ to find $l$: $A = 2l + 2w \Rightarrow 2l = A - 2w \Rightarrow l = \frac{A - 2w}{2}$
3. Exponent laws and scientific notation
Use laws like $a^m \times a^n = a^{m+n}$ and convert numbers to form $a \times 10^n$.
Example: $2 \times 10^3 \times 3 \times 10^2 = 6 \times 10^{3+2} = 6 \times 10^5$
4. Rational exponents
Rewrite $a^{m/n} = \sqrt[n]{a^m}$.
Example: $8^{2/3} = (\sqrt[3]{8})^2 = 2^2 = 4$
5. Solving linear equations
Isolate variable using inverse operations.
Example: Solve $2x + 3 = 7$: $2x = 4 \Rightarrow x = 2$
6. Solving quadratic equations
(a) Factorisation: Find factors that multiply to $c$ and add to $b$ in $ax^2 + bx + c=0$.
Example: $x^2 + 5x + 6 = (x+2)(x+3) = 0 \Rightarrow x=-2,-3$
(b) Completing the square: Rewrite as $(x+p)^2 = q$.
Example: $x^2 + 6x + 5=0 \Rightarrow (x+3)^2 = 4 \Rightarrow x=-3 \pm 2$
(c) Quadratic formula: $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.
Example: For $x^2 + 4x - 5=0$, $x=\frac{-4 \pm \sqrt{16+20}}{2} = \frac{-4 \pm 6}{2}$
7. Linear simultaneous equations
(a) Graphical: Plot lines and find intersection.
(b) Substitution: Solve one for a variable and substitute.
(c) Elimination: Add or subtract equations to eliminate a variable.
Example: Solve $x+y=5$, $x-y=1$ by elimination: Adding gives $2x=6 \Rightarrow x=3$, then $y=2$
8. Non-linear simultaneous equations
Solve systems with one linear and one quadratic equation by substitution.
Example: $y = 2x + 1$, $y = x^2$; set equal: $x^2 = 2x + 1$ solve quadratic.
9. Problem-solving using simultaneous equations
Translate word problems into equations and solve simultaneously.
10. Linear inequalities
Solve like equations but reverse inequality when multiplying/dividing by negative.
Example: $2x - 3 > 5 \Rightarrow 2x > 8 \Rightarrow x > 4$
11. Quadratic inequalities
Solve quadratic equation, test intervals to find where inequality holds.
12. Regions of Cartesian plane
Graph inequalities to shade regions satisfying conditions.
13. Feasible region
Intersection of constraints in optimization problems.
14. Linear programming
Maximize or minimize objective function over feasible region.
15. Distance formula
Distance between $(x_1,y_1)$ and $(x_2,y_2)$ is $\sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$.
Example: Distance between (1,2) and (4,6) is $\sqrt{(4-1)^2 + (6-2)^2} = 5$
16. Midpoint theorem
Midpoint is $\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right)$.
Example: Midpoint of (2,3) and (4,7) is (3,5)
17. Gradient of parallel and perpendicular lines
Parallel lines have equal gradients; perpendicular gradients multiply to -1.
18. Congruent triangles
Triangles with equal sides and angles.
19. Proof using congruence
Use criteria like SSS, SAS, ASA to prove triangle congruence.
20. Similar triangles
Triangles with equal angles and proportional sides.
21. Trigonometric ratios
Use $\sin = \frac{opposite}{hypotenuse}$, $\cos = \frac{adjacent}{hypotenuse}$, $\tan = \frac{opposite}{adjacent}$.
Example: Find side opposite angle 30° in right triangle with hypotenuse 10: $10 \times \sin 30° = 5$
22. True bearings
Measure clockwise from north.
23. 3D trigonometry
Use trigonometry in three dimensions for distances and angles.
24. Trigonometric functions
Functions like $y=\sin x$, $y=\cos x$, $y=\tan x$.
25. Trigonometry with obtuse angles
Use identities and unit circle.
26. Area of triangle
$\frac{1}{2}ab\sin C$
27. Sine rule
$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$
28. Cosine rule
$c^2 = a^2 + b^2 - 2ab \cos C$
29. Pythagorean and Tan identities
$\sin^2 x + \cos^2 x = 1$, $\tan x = \frac{\sin x}{\cos x}$
30. Special angles and CAST diagram
Use quadrant signs for trig functions.
31. Trigonometric equations
Solve equations involving trig functions.
32. Function notation
$f(x)$ represents function value at $x$.
33. Domain and range
Domain: input values; Range: output values.
34. Graphing quadratic functions
Use transformations of $y=x^2$.
35. Completing the square
Rewrite quadratic in vertex form.
36. Axes intercepts
Find where graph crosses axes.
37. Axis of symmetry and vertex
Axis: $x = -\frac{b}{2a}$; vertex is point on parabola.
38. Finding quadratic function
From points or vertex form.
39. Graphs of exponential functions
$y = a^x$ with $a>0, a \neq 1$
40. Exponential equations
Solve using logarithms.
41. Reciprocal functions
$y = \frac{1}{x}$
42. Discrete vs continuous data
Discrete: countable; continuous: measurable.
43. Measuring centre
Mean, median, mode.
44. Cumulative data
Data accumulated up to a point.
45. Measuring spread
Range, interquartile range.
46. Box-and-whiskers
Graphical summary of data.
47. Standard deviation
Measure of spread around mean.
48. Normal distribution
Bell-shaped curve.
49. Venn diagrams
Visualize sets and their relations.
50. Intersection and union
Intersection: common elements; union: all elements.
51. Theoretical probability
Probability based on known outcomes.
52. Addition law
$P(A \cup B) = P(A) + P(B) - P(A \cap B)$
53. Mutually exclusive events
Events that cannot happen together.
54. Tree diagrams
Visualize sequences of events.
Each topic can be expanded with examples and detailed steps as needed for exam preparation.
Algebra Summary
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