chapt 1.9 & 1.10 - practical situations , set notation Flashcards
simple interest
I = PRT / 100
- > I = interest
- > P = principal amount
- > R = rate of interest (per annum)
- > T = period of time (years)
compound interest
A = P(1+ R/100)^n
- > A = total amount after n units of time
- > P = principal amount
- > R = rate of interest (per unit time)
- > n = number of units of time
money equations
foreign currency = SGD x exchange rate
profit = selling price - cost price
loss = cost price - selling price
distance time graph
1) gradient = speed of object
2)
- straight line: uniform speed
- curve line: varying speed
- line // time axis: stationary
3) avg speed = total dist / total time
speed time graph
1) gradient = acceleration of object
2)
- straight line: uniform acceleration
- curve: varying acceleration
- straight // time axis: moving at uniform speed
3) total dist covered = area under graph
elements
1) a ∈ A
- > a is an element of A
2) b ∉ A
- > b is not an element of A
3) n(A)
- > denotes the number of elements in set A
Equal
1) all sets contain the same exact elements
e. g; A = {a , b , c} , B = {c , a , b} , C = {1 , 2 , 3}
- > A and B are equal sets , A and C are not equal sets
subsets
1) A ⊆ B ; A is a subset of B
- > every element of set A is in set B
2) A ⊂ B ; A is a proper subset of B
- > every element of set A is in set B but A ≠ B
3) A ⊄ B ; A is not a proper subset of B
complement sets
1) A’ denotes the complement of set A to universal set , U
- > it is the set of all elements in U except those in A
union and intersection
1) union of A and B denoted as A ∪ B
- > the set of elements which belong to set A or set B or both
e. g venn diagram
- both circles are shaded fully
2) intersection of A and B denoted as A ∩ B
- > the set of elements which belong to both A and B
e. g; venn diagram
- middle (intersection) is shaded , everythg else is unshaded
