equations

Question 1

volume of a cone

Answer 1

1/3 * π * r squared * h

Question 2

surface area of a cone

Answer 2

( π * r squared ) + ( π * r * l)

Question 3

volume of a pyramid

Answer 3

1/3 * area of base * height

Question 4

volume of a cylinder

Answer 4

π * r squared * h

Question 5

surface area of a cylinder

Answer 5

( 2* π * r squared ) + ( π * d * h )

Question 6

volume of a sphere

Answer 6

4/3 * π * r cubed

Question 7

surface area of a sphere

Answer 7

4 * π * r squared

Question 8

a^2 =

Answer 8

b^2 + c^2 - 2bcCosA

Question 9

area of a triangle (no right angle)

Answer 9

1/2 * abSinC

Question 10

area of a sector of a circle

Answer 10

theta/360 * π * r squared

Question 11

sum of interior angles in a polygon

Answer 11

(n-2) * 180

Question 12

size of one exterior angle of a polygon

Answer 12

360/n

Question 13

pressure =

Answer 13

force/area

Question 14

decay (also known as depreciation - the opposite is compound interest) =

Answer 14

original amount( 1 - (rate of decay/100))^time

Question 15

simple interest =

Answer 15

(original amount * rate of growth * time)/100

Question 16

length of an arc of a sector =

Answer 16

(theta/360) * 2 * π * r

Question 17

Addition formula (probability)​

Answer 17

P (A U B) = P(A) + P(B) - P(A N B)

Question 18

Probability of A given B has happened

Answer 18

P(A|B) = P(A N B)/ P (B)

Question 19

Length of a space diagonal in a cuboid/cube ​

Answer 19

d = sqrt (a^2 + b^2 + c^2)

Question 20

1 litre = how many cl

Answer 20

100cl

Question 21

1 cl = how many ml

Answer 21

10ml

Question 22

5 miles = ?km

Answer 22

8km

Question 23

1 foot = ?inches

Answer 23

12 inches

Question 24

1 foot = ?cm

Answer 24

30cm

Question 25

1m^2 = ?cm^2

Answer 25

10,000 cm^2

Question 26

1cm^2 = ? mm^2

Answer 26

100 mm^2

Question 27

area of a kite

Answer 27

half product of its diagonals

Question 28

matrix transformation for an enlargement of scale factor k with centre (0,0)

Answer 28

k 0 0 k

Question 29

matrix transformation for an identity (stays the same)

Answer 29

1 0 0 1

Question 30

if composite transformation A is followed by transformation B what do you do

Answer 30

multiply the matrices in order BA

Question 31

how to tell if the point on a curve is the maximum

Answer 31

gradient goes from positive to negative d^2y/dx^2 <0

Question 32

how to tell if the point on a curve is the minimum

Answer 32

goes from negative to positive

Question 33

how do you know if a function is increasing

Answer 33

dy/dx is greater than 0

Question 34

what is the equation of a circle with radius r and centre (a,b)

Answer 34

(x-a)^2 + (y-b)^2 = r^2

Question 35

there are two equations of the line. one is y = mx + c. what is the other one

Answer 35

y2 - y1 =m(x2 - x1)

Question 36

frequency density =

Answer 36

frequency / class width

Question 37

amount in sample =

Answer 37

(group number/total) * sample size

Question 38

percentage change =

Answer 38

(difference/original) * 100