memorise maths Flashcards
what are 3 assumptions of binomial distribution?
the probability of the event occuring is at a fixed value X
the probability of the event happening each time is independent of it happening another time
there are only 2 possible outcomes
describe how you would take a random sample
give each member of the population a number from 1 to n(the population size)
generate random 4 digit integers using a calculator
ignore repeats and random numbers outside the range
continue until the sample size needed is collected each having a different number and use these numbers to identify and select members of the population with corresponding numbers
issues with large data set?
can have a lack of common units- for instance butter is measured in grams and oil in millilitres, so cannot be compared
how do you get from normal distribution to standard normal distribution?
Z=(X-μ)/σ
what is the proof for 2 events being independent?
P(AnB)=P(A) x P(B)
what are the double angle formulas for cos2A
= cos^2 A − sin^2 A
= 1 - 2 sin^2 A
= 2 cos^2 A − 1
what is the double angle formula for sin2A
2sinAcosA
what is the double angle formula for tan2A
2tanA / (1 − tan^2 A)
what is sec^2x equivilent to?
1 + tan^2x
what is cosec^2x equivilent to?
1 + cot^2x
what is the nth term of an arithmetic sequence with first term a and difference d?
Un = a + ( n - 1 ) d
what is the nth term of a geometric sequence with first term a and common ratio r?
Un = ar^(n-1)
what is the equation for variance with known data
Σfx^2/Σf - mean^2
why do you make the assumption that the plank is rigid?
the plank remains the same shape/straight so all forces are perpendicular to AB and all distances are paralell to AB
why do you assume an object is a particle?
so force acts at point x
