Maths Formulas

we're gonna die

How to round for BAC

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Distance

speed x time

Speed

distance/time

Time

distance/speed

Stopping Distance w/ BD

reaction distance + breaking distance

Stopping Distance w/o BD

5V(km/h) x reaction time (sec)/18 + v²/170

km/h → m/s

5/18

Gradient

y2-y1/x2-x1

Linear Modelling Horizontal & Vertical

Independent & Dependent

Direct Linear Variation

y=kx (y = dependent, x = independent)

mL → cm

1:1

kL → m

1:1

kL → L

1:1000

Absolute Error

+- ½ of smallest unit of measurement

Percentage Error

absolute error/measurement x 100

T → kg

1:1000

H → m

1:10000

Circle Perimeter

2πr or πd

Arc Perimeter

angle/360 × 2πr

Quarter Perimeter

¼ x 2πr

Semi Circle Perimeter

½ x 2πr

Triangle Area

½ bh

Parallelogram Area

bh

Kite Area

½ xy

Trapezium Area

(a+b)/2 x h

Circle Area

πr²

Semi Circle Area

½ πr²

Quarter Area

¼ πr²

Arc Area

angle/360 πr²

Trapezoidal Rule

h/2 (front distance + back distance)

Prism Surface Area

sum of face areas

Cylinder Surface Area

2πr² + 2πrh

Sphere Surface Area

4πr²

Hemisphere Surface Area

3πr²

Prism Volume

ba x h

Cylinder Volume

πr²h

Sphere Volume

4/3 πr³

m → kL

1:1

High Outlier

Q3 + 1.5 x IQR

Low Outlier

Q1 - 1.5 x IQR

IQR

Q3 - Q1

measures of central tendency

• mean (average)

• mode (most common)

• median (medium)

measures of spread

• range

• IQR

• spread ???

• standard deviation

compound interest

A = P(1 + r)^n

skew

• positive (tail to right)

• negative (tail to left)

simple interest

SI = Prt