Formula To Memorise

Question 1

Length equation

Answer 1

root[(x2-x1)^2+ (y2-y1)^2]

Question 2

midpoint equation

Answer 2

[(x1+x2)/2 , (y1+y2)/n]

Question 3

gradient

Answer 3

Change in y /change in x

Question 4

Equation of line

Answer 4

y-y1 =m(X-x1)

Question 5

quadratic formula

Answer 5

X= [-b+- root(b^2-4ac)]/2a

Question 6

sine rule

Answer 6

a/sinA = b/sinB
OR
sinA/a =sinB/b

Question 7

cosine rule

Answer 7

a^2 =b^2 + c^2 -2bc cos A

Question 8

area of triangle

Answer 8

1/2 ab sinC

Question 9

sin x =k 1st, 2nd and other solution

Answer 9

1st sin^-1
2nd 180-
other +- 350

Question 10

cos X =k first second and other solution

Answer 10

1st cos-1
2nd 360 -
Other +- 360

Question 11

tan x =k first second and other solution

Answer 11

1st tan^-1
2nd and other +- 180

Question 12

tan x =

Answer 12

sin x/cos x

Question 13

sin^2 x + cos^2 x =

Answer 13

1

Question 14

sec x =

Answer 14

1/cos x

Question 15

cosec x =

Answer 15

1/sin x

Question 16

cot x =

Answer 16

1/tan x
cos x/sin x

Question 17

cosec^2 x

Answer 17

1+ cot^2 x

Question 18

sec^2 x =

Answer 18

1+ tan^2 x

Question 19

sin 2x =

Answer 19

2sinxcosx

Question 20

cos2x=

Answer 20

cos^2 x -sin^2 x
2cos^2 x -1
1- 2sin^2 x

Question 21

tan 2x =

Answer 21

2tanx/(1- tan^2x)

Question 22

arc length =

Answer 22

r@

Question 23

sector area

Answer 23

1/2 r^2 @

Question 24

Arthmetric nth term

Answer 24

Un= a + (n-1)d

Question 25

Geometric nth term

Answer 25

Un=ar^(n-1)

Question 26

derivative of a^X

Answer 26

a^X ln a

Question 27

Product rule

Answer 27

y=uv
dy/dx = vu’ +uv’

Question 28

integrate a^x

Answer 28

a^x/ lna +c

Question 29

trap rule

Answer 29

(h/2)(first+last +2(middles)) where h=(b-a)/n

Question 30

differentiate parametric equations

Answer 30

y’/x’

Question 31

integrate parametric equations

Answer 31

integration of (y dx/dt) dt

Question 32

when finding the angle the vectors xi + yj + zk makes with postive x, y or z axis cos@(x or y or z)=

Answer 32

x or y or z / |a|

Question 33

linear interpolation

Answer 33

Q-LV/HV-LV = N-LF/UF - LF

Question 34

frequency density

Answer 34

Frequency/ class width

Question 35

P(B|A) =

Answer 35

P(A n B)/P(A)

Question 36

for independent events A and B :

Answer 36

P(A n B) = P(A) x P(B)

Question 37

standardisation formula

Answer 37

z= x- u / @

Question 38

Equation of motion

Answer 38

F=ma

Question 39

Fmax =

Answer 39

uR

Question 40

moment =

Answer 40

force x perpendicular distance

Question 41

Surface area of sphere

Answer 41

4 pi r^2

Question 42

Volume of sphere

Answer 42

4/3 pi r^3

Question 43

area of rhombus

Answer 43

length of 2 diagonal sides timesed together