Maths Flashcards
How do you calculate the area of a triangle?
1/2 x Base x Height
Area of a circle?
Pi times r squared
Circumference of a circle?
2 pi times r
How does (x^3-x) simplify?
X(x^2-1)
How do you get time when you have distance and speed?
Distance/Speed
5/12 divided by 3/8 can also be expressed how?
5/12 x 8/3
How to calculate (n+1)^2 mentally?
N^2 + n + (n+1)
How many combinations if I have a set of n, with r selected?
N!/(r!(n-r)!)
Sum of all units in a sequence?
Average x Number of terms
Number of terms in a sequence?
((Last item- First Item )/2)+1
a^x times a^y
a^(x+y)
Reciprocal of x
1/x
What is Gemdas?
Order of operations which is:
Groups (e.g. Parenthesis) Exponents (e.g. Square root or square) Multiplication Division Addition Substraction
What is absolute value of x-5?
Distance of x from 5
Abosulte value of x+ 12?
Distance of x from -12
If x = GCD of A&B
And
Y is LCM of A&B
What is AB?
AB is equal to xy
Sum of angles of any shape
(N-2)*180
Area of an equilateral triangle?
((Root of 3 ) /4) * side^2
Ratio of 30-60-90 triangles sides
1-2-root of 3
Whats an equilateral triangle?
Szabalyos haromszog
What is median?
The middle number of a set
What is mean?
Arithmetic average of a set
Probabality of a event a or b happening?
P(a) plus (p(b)
Probability of event a and b happening
P(a)*P(b)
What is 10^-3?
0.001
5/6
0.8333
1/7
0.142
7/9
0.77777
If we add a to numerator and b to denominator, what do we get?
A number closer to a/b
How to figure out if 3/14 or 4/15 is bigger?
Cross multiply.
Is 1 a prime number?
NO!!!
Factor x^2-y^2
(x-y)(x+y)
Is 4^(-5) positive or negative?
Positive
What is divisibility by prime boxes?
To break down numerator and denominator into multiples of prime numbers, and see if you can eliminate all denominators to 1.
No problem is denominator figure staye, but numerator must be 1.
(A^x)*(B^x) =
(Ab)^x
0.6 with a line above the 6 equals?
2/3
What is arc length?
Körív
Formula to use to find line from on epoint
Y = mx + b
M being the slope and then plugging in known point coordinates
Prime numbers below 60
2-3-5-7-11-13-17-19-23-29-31-37-41-43-47-53-59
How to find out if a number below 100 is prime.
See if its dividible by 2-3-5-7.
What is mode?
The most common number in a set
How to get number of factors of a large number
Gow to do same for odd or for even numbers
Prime factors, then adding 1 to the powers, the multiplying powers
For odd, ignore 2
For even, substract odd from total
Least common multiple
(PxQ)/ Greatest common factor
Ratio of circumference to diameter?
Pi
What is a multiple of a number?
If k is a multiple of 1440, then k is equal to x times 1440
If two numbers are inversely proportional, waht is true?
That their product is constant
How to calculate time
Quantity / rate
How to calculate rate
Quantity / Time
How to calculate quantity
Rate x time
Even + even
Odd +odd
Even+odd
Even x even
Odd x odd
Even x odd
Even + even = even
Odd +odd = even
Even+odd = odd
Even x even = even
Odd x odd = odd
Even x odd = even
a^x-b^x
(A-b)x(a+b)
Square root of x
Is x to the power of what?
X to the power of 0.5
What % of values are in one standard deviation, and what percentage in two?
68% and 95%
When does the <> sign change direction in inequalities?
If you multiply or divide by a negative number
What is -3
|x-4|<7
Divident formula
Divident = (divisor x quotient) + remainder
Formula of distance
Formula of rate
Formula of time
D=rt
T=d/r
R=d/t
X^n + x^(n+1) =
X^n * (x+1)
Square root of x^2 is?
|x|
3^4
81
2^9
Down to
2^2
512
To
4
4^3
4^4
64
256
5^3
5^4
125
625
6^3
7^3
8^3
9^3
216
343
512
729
Area of equilateral triangle
(Square root 3 /4) * side^2
B^(1/2)
Square root of b
How do you rationalise
1/(3-root 5)?
Multiply by (3+root5)/(3+root5)
Formula of 3d rectangular cube cross line?
Diagonal cross squared = side a squared + side b squared + side c squared
Slope formula
Delta y / delta x
Formula for possibilities of seating around circular table?
(N-1) l!
What is a point reflected over line x=y
Or
Y=-x
What are these lines?
These are diagonal lines from origin
X=y switches y and x coordinate
X=-y switches y and x coordinate and also the signs in front of them
(Root (x+y) ) * (root(x-y))=?
Root(x^2-y^2)
List 4 pithagorean triplets
3-4-5
6-8-10
5-12-13
7-24-25
If in a set of n items b are identical, how many distinct arrangements can be made?
N!\b!