maths equations

Question 1

quadratic equation

Answer 1

x= -b± square root b^2 - 4ac / 2a

Question 2

cosine rule

Answer 2

a^2 = b^2 + c^2 - 2bccosA

Question 3

area of a triangle

Answer 3

1/2 absinC

Question 4

midpoint

Answer 4

(x1x2)/2 , (y1+y2)/2

Question 5

log(x) + log(y) =

Answer 5

log(xy)

Question 6

log(x) - log(y) =

Answer 6

log(x/y)

Question 7

log(a) = (when the base is a also)

Answer 7

1

Question 8

log(1) =

Answer 8

0

Question 9

log(1/x) =

Answer 9

-log(x)

Question 10

1 + cot^2x =

Answer 10

cosec^2x

Question 11

tan^2x + 1 =

Answer 11

sec^2x

Question 12

sin2x

Answer 12

2sinxcosx

Question 13

cos2x

Answer 13

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

Question 14

tan2x

Answer 14

(2tanx)/1-tan^2x

Question 15

degrees to rad

Answer 15

(degree/180) x pi

Question 16

rad to degrees

Answer 16

(rad/pi) x 180

Question 17

arc length

Answer 17

r0

Question 18

area of sector

Answer 18

1/2r^20

Question 19

vector- AB =

Answer 19

OB - OA

Question 20

mutually exclusive

Answer 20

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

Question 21

independent

Answer 21

P(A N B) = P(A) X P(B)

Question 22

y’ (when differentiating with respect to x)

Answer 22

dy/dx

Question 23

standard normal coding

Answer 23

Z = (X - mean) / standard deviation

Question 24

for hypo testing normal distribution

Answer 24

X(x bar)~N(mean, standard deviation/square root of number in sample)

Question 25

coding ( y = (x-a)/b)

Answer 25

(mean y) = (mean x - a)/b (standard deviation y) = (standard deviation x)/b

Question 26

chain rule (f(g(x))

Answer 26

g'(x) x f'(g(x))

Question 27

product rule (f(x)g(x))

Answer 27

f(x)g'(x) + f'(x)g(x)

Question 28

length

Answer 28

square root of x1-x2 squared + y1- y2 squared

Question 29

equation of a straight line

Answer 29

y - y1 = m(x-x1)

Question 30

equation of a circle

Answer 30

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

Question 31

what are the 3 circle theorems

Answer 31

- the perpendicular bisector of a chord will pass through the centre of a circle - a tangent to a circle is perpendicular to the radius of the circle at the point of intersection - the angle in a semi circle is 90 degrees