IGCSE Maths 英语数学词汇知识点总结(配图).docx

IGCSE Maths 英语数学词汇知识点总结（配图）1. ∅: The empty set (proper subset)2. ∈: is an element of {set}3. ∉: is not an element of {set}4. 0.7 recurring as a fraction: 10f = 7.777..., 10f-f=7, 9f=7, f/=975. 0.3181818 recurring as a fraction : 100f =31.818181..., 100f- f=31.5, 99f=31.5, f=315/990=/7226. 1/2(a+b)h : Area of a trapezium7. 1 centiliter =: 10 ml8. 1 cm cubed = : 1 ml9. 2- : 1/4 (The reciprocal of the number without the negative)10. (2x ) = : 8x to the power of 1511. -3=-9 : (-3) =912. 1000 cm cubed = : 1L13. 1000 kg = : 1 tonne14. 1000 Litres = : 1 metre cubed15. 1000 milliliters =: 1L16. A ∩ B: Intersection of A and B (items in both)17. A ∪ B: Union of A and B (items in A or B or both)18. A ⊂ B: A is a proper subset of B19. A ⊆ B: A is a subset of B20. a/b + c/d : (ad + bc)/bd21. a/b - c/d : (ad - bc)/bd22. a/b x c/d : ac/bd23. Adding and subtracting fractions : For fractions to be added or subtracted, the denominator MUST be the same.24. Adding and subtracting indices : Powers and variables must be the same25. Adding and subtracting matrices : For matrices to be added or subtracted they must be of the same order.26. Angles in a circle - centre, circumference :If an angle is extended to the centre of a circle from arc AB and another angle is extended to the circumference from arc AB then the angle at the circumference will be half the angle at the centre.27. Angles in a circle - cyclic quadrilateral:sOpposite angles in a cyclic quad add to 180 degrees.28. Angles in a circle - same arc at circumference :All angles extending out to the circumference from arc AB will have the same angle.29. Angles in a circle - two semi-circles :If a diameter is drawn and an angle in the semi-circle uses it as its base (with its third point touching the circumference) then the angle at the circumference is 90 degrees.30. Angles in a quadrilateral..:.add to 360 degrees31. Angles in a triangle..:.add to 180 degrees32. A polygon is regular if..:.all interior angles are equal and all its sides are the same length. e.g. square, pentagon, hexagon, octagon.33. A power to a power (x) : If a power is raised a variable that is already being squared, you multiply the indices. The example will equal x to the power of 6.34. A ratio as a fraction: You can express particular numbers in the ratio as fractions by finding what the whole ratio adds up to and using that as the denominator. e.g. 3/5 is the first part of the ratio 3:235. Arc : An arc is a section of the circumference of a circle36. Area and volume scale factor : Used in similar shapes. This applies the same principles as the linear scale factor but is squared or cubed. To find the linear scale factor from these, find the square or cube root.37. area of cross-section x length : volume of a prism38. a/sinA=b/sinB=c/sinC : The sine rule (can be inverted so sines are on top)39. Average speed : Distance/time40. ax to the power of -5 : a/x to the power of 541. Bar charts :All bars are the same width, the heights represent frequency. A dual chart is sometimes useful to compare two bar charts with similar data.42. base x height : Area of a square, rectangle and parallelogram43. Calculating probability : Probability can be found with a probability fraction. The fraction of P(outcome) is the number of ways the outcome can happen/the total number of possible outcomes. This can then be changed to a decimal or percentage.44. Calculating the angles of a pie chart : To find what angle a sector will be, take the frequency divided by the total number and then times that by 360. These angles do not have to labelled on the chart45. Choosing the right rule - two angles and a side : Sine rule46. Choosing the right rule - two sides and included angle :Cosine rule followed by sine rule47. Chords :A chord is a line in a circle where both ends touch the circumference, cutting a section of the circle.48. Combined frequency of two events : You can illustrate the possibilities of two combined events on a possibility diagram where all the possible outcomes for one variable is on one axis and for the other on the other axis. Every possible outcome for both variables is then represented on the diagram and the probability can be found.49. Composite function expressions : To make an expression for the composite function fg(x), put the expression for g, in the place of x in the expression for f. "Take x, apply g, then apply f"50. Composite functions : When functions are put together, read them backwards. e.g. fg(2) means start with 2, apply g then apply f51. Compound interest : amount x 1. percentage to number of years52. Compound interest formula : P(1+r/100)^n where r is the percentage, n is the time and P is the amount invested.53. Congruent shapes : Shapes with the same size and shape as。