All gust lines in the V-n graph originate from a point where the

  1. Fractions
    Add/subtract: make the bottom number the same first
    Multiply: top × top, bottom × bottom
    Divide: keep, change, flip

Example:
1/2 + 1/4 = 2/4 + 1/4 = 3/4
2/3 × 4/5 = 8/15
2/3 ÷ 4/5 = 2/3 × 5/4 = 5/6

  1. Sig fig and decimal places
    Decimal places: count digits after the decimal point
    Significant figures: start at first non-zero digit
    If next digit is 5 or more, round up

Example:
3.456 to 2 decimal places = 3.46
0.00456 to 2 sig fig = 0.0046

  1. Factorization
    Common factor: take out the biggest factor
    Quadratic: find two numbers that multiply to last term and add to middle term

Example:
6x + 9 = 3(2x + 3)
x² + 5x + 6 = (x + 2)(x + 3)

  1. Transposition
    Move terms across and do the opposite operation

Example:
y = 2x + 4
y – 4 = 2x
x = (y – 4)/2

  1. Inequalities
    Solve like normal
    If you multiply or divide by a negative, flip the sign

Example:
-2x > 8
x < -4

  1. Triangle construction
    Draw the side given
    Measure the angle
    Draw the next side
    Join the last point
  2. Functions
    Substitute the number for x
    Inverse: swap x and y, then make y the subject
    Composite: put one function inside the other

Example:
f(x) = 2x + 1
f(3) = 7

  1. Transformations
    Translation = slide
    Reflection = flip
    Rotation = turn

Rules:
(x, y) → (x + a, y + b)
(x, y) → (x, -y)
(x, y) → (-x, y)
(x, y) → (-y, x)
(x, y) → (y, -x)
(x, y) → (-x, -y)

  1. Gradient and line
    Gradient:
    m = (y2 – y1)/(x2 – x1)

Equation of line:
y = mx + c

  1. Statistics
    Mean = Σfx / Σf
    Median: find total frequency, divide by 2, locate that value
    Histogram: bars touch
    Frequency polygon: join points with straight lines
    Cumulative frequency curve: keep adding frequencies
  2. Trigonometry
    SOH CAH TOA
    sin = opp/hyp
    cos = adj/hyp
    tan = opp/adj
  3. Pythagoras
    + =
    c is the longest side
  4. Sine rule and cosine rule
    Sine rule:
    a/sinA = b/sinB = c/sinC

Cosine rule:
a² = b² + c² – 2bc cosA

  1. Circle theorem
    Angle in semicircle = 90°
    Angle at centre = 2 × angle at circumference
    Angles in same segment are equal
    Opposite angles in cyclic quadrilateral add to 180°
  2. Matrices
    Add/subtract: match positions
    Multiply: row by column

Inverse of 2×2:
[a b]
[c d]

Inverse =
1/(ad – bc)
[d -b]
[-c a]

  1. Simultaneous equations
    Use substitution or elimination

Example:
x + y = 7
x – y = 1
Add:
2x = 8
x = 4

  1. Distance-time graph
    Gradient = speed
    Flat line = stopped
    Steeper line = faster
  2. Vectors
    Add matching parts

Example:
[2]
[3]
+
[1]
[4]

[3]
[7]

Magnitude:
√(a² + b²)

THINGS TO MEMORIZE
SOH CAH TOA
a² + b² = c²
a/sinA = b/sinB
a² = b² + c² – 2bc cosA
m = (y2 – y1)/(x2 – x1)
y = mx + c
mean = Σfx / Σf

SUPER SHORT REMINDERS
Fractions: same bottom first
Sig fig: start at first non-zero digit
Transposition: do opposite
Inequalities: flip sign for negative
Functions: substitute
Trig: use SOH CAH TOA
Pythagoras: longest side is c
Line: y = mx + c
Distance-time graph:
gradient is speed


Example:
-2x > 8
x < -4

  1. Triangle construction
    Draw the side given
    Measure the angle
    Draw the next side
    Join the last point
  2. Functions
    Substitute the number for x
    Inverse: swap x and y, then make y the subject
    Composite: put one function inside the other

Example:
f(x) = 2x + 1
f(3) = 7

  1. Transformations
    Translation = slide
    Reflection = flip
    Rotation = turn

Rules:
(x, y) → (x + a, y + b)
(x, y) → (x, -y)
(x, y) → (-x, y)
(x, y) → (-y, x)
(x, y) → (y, -x)
(x, y) → (-x, -y)

  1. Gradient and line
    Gradient:
    m = (y2 – y1)/(x2 – x1)

Equation of line:
y = mx + c

  1. Statistics
    Mean = Σfx / Σf
    Median: find total frequency, divide by 2, locate that value
    Histogram: bars touch
    Frequency polygon: join points with straight lines
    Cumulative frequency curve: keep adding frequencies
  2. Trigonometry
    SOH CAH TOA
    sin = opp/hyp
    cos = adj/hyp
    tan = opp/adj
  3. Pythagoras
    a² + b² = c²
    c is the longest side
  4. Sine rule and cosine rule
    Sine rule:
    a/sinA = b/sinB = c/sinC

Cosine rule:
a² = b² + c² – 2bc cosA

  1. Circle theorem
    Angle in semicircle = 90°
    Angle at centre = 2 × angle at circumference
    Angles in same segment are equal
    Opposite angles in cyclic quadrilateral add to 180°
  2. Matrices
    Add/subtract: match positions
    Multiply: row by column

Inverse of 2×2:
[a b]
[c d]

Inverse =
1/(ad – bc)
[d -b]
[-c a]

  1. Simultaneous equations
    Use substitution or elimination

Example:
x + y = 7
x – y = 1
Add:
2x = 8
x = 4

  1. Distance-time graph
    Gradient = speed
    Flat line = stopped
    Steeper line = faster
  2. Vectors
    Add matching parts

Example:
[2]
[3]
+
[1]
[4]

[3]
[7]

Magnitude:
√(a² + b²)

THINGS TO MEMORIZE
SOH CAH TOA
a² + b² = c²
a/sinA = b/sinB
a² = b² + c² – 2bc cosA
m = (y2 – y1)/(x2 – x1)
y = mx + c
mean = Σfx / Σf

SUPER SHORT REMINDERS
Fractions: same bottom first
Sig fig: start at first non-zero digit
Transposition: do opposite
Inequalities: flip sign for negative
Functions: substitute
Trig: use SOH CAH TOA
Pythagoras: longest side is c
Line: y = mx + c
Distance-time graph: gradient is speed


  1. Statistics
    Mean = Σfx / Σf
    Median: find total frequency, divide by 2, locate that value
    Histogram: bars touch
    Frequency polygon: join points with straight lines
    Cumulative frequency curve: keep adding frequencies
  2. Trigonometry
    SOH CAH TOA
    sin = opp/hyp
    cos = adj/hyp
    tan = opp/adj
  3. Pythagoras
    a² + b² = c²
    c is the longest side
  4. Sine rule and cosine rule
    Sine rule:
    a/sinA = b/sinB = c/sinC

Cosine rule:
a² = b² + c² – 2bc cosA

  1. Circle theorem
    Angle in semicircle = 90°
    Angle at centre = 2 × angle at circumference
    Angles in same segment are equal
    Opposite angles in cyclic quadrilateral add to 180°
  2. Matrices
    Add/subtract: match positions
    Multiply: row by column

Inverse of 2×2:
[a b]
[c d]

Inverse =
1/(ad – bc)
[d -b]
[-c a]

  1. Simultaneous equations
    Use substitution or elimination

Example:
x + y = 7
x – y = 1
Add:
2x = 8
x = 4

  1. Distance-time graph
    Gradient = speed
    Flat line = stopped
    Steeper line = faster
  2. Vectors
    Add matching parts

Example:
[2]
[3]
+
[1]
[4]

[3]
[7]

Magnitude:
√(a² + b²)

THINGS TO MEMORIZE
SOH CAH TOA
a² + b² = c²
a/sinA = b/sinB
a² = b² + c² – 2bc cosA
m = (y2 – y1)/(x2 – x1)
y = mx + c
mean = Σfx / Σf

SUPER SHORT REMINDERS
Fractions: same bottom first
Sig fig: start at first non-zero digit
Transposition: do opposite
Inequalities: flip sign for negative
Functions: substitute
Trig: use SOH CAH TOA
Pythagoras: longest side is c
Line: y = mx + c
Distance-time graph: gradient is speed


  1. Simultaneous equations
    Use substitution or elimination

Example:
x + y = 7
x – y = 1
Add:
2x = 8
x = 4

  1. Distance-time graph
    Gradient = speed
    Flat line = stopped
    Steeper line = faster
  2. Vectors
    Add matching parts

Example:
[2]
[3]
+
[1]
[4]

[3]
[7]

Magnitude:
√(a² + b²)

THINGS TO MEMORIZE
SOH CAH TOA
a² + b² = c²
a/sinA = b/sinB
a² = b² + c² – 2bc cosA
m = (y2 – y1)/(x2 – x1)
y = mx + c
mean = Σfx / Σf

SUPER SHORT REMINDERS
Fractions: same bottom first
Sig fig: start at first non-zero digit
Transposition: do opposite
Inequalities: flip sign for negative
Functions: substitute
Trig: use SOH CAH TOA
Pythagoras: longest side is c
Line: y = mx + c
Distance-time graph: gradient is speed


1(a)
1 – (1/30 + 4/15)

First make the fractions have the same denominator:
4/15 = 8/30

So:
1/30 + 8/30 = 9/30 = 3/10

Now:
1 – 3/10 = 7/10

Answer: 7/10

1(b)
At 06:30, 1/30 of 1020 spaces were filled:
1/30 × 1020 = 34

During the next hour, another 4/15 of 1020 spaces were filled:
4/15 × 1020 = 272

Total filled at 07:30:
34 + 272 = 306

Not filled:
1020 – 306 = 714

Answer: 714 parking spaces

1(c)
20% of 1020:
20/100 × 1020 = 204

Answer: 204 parking spaces