Maths calculator Flashcards
What does invarient mean
after a transformation the properties of objects that do not change
what would be invarient for an enlargment and what would not
the angle would be invarient as it has not changed but the length would not as it has either got bigger or smaller
what does speed equal
distance/time
It takes a bus 90 minutes to travel 42 miles work out the average speed of the bus
42/1.5=28
How do you calculate distance
speed x time
Tiegan walked for 7 hours at an average speed of 2.8 miles per hour how many miles did tiegan walk
7 x 2.8=19.6
How do you work out time
distance/speed
cameron completed a 74km race at an average speed of 11.84 work out how long he took
74/11.84=6.25=6 hours and 15 mins
What does modal mean
most common
A bus travels from brook lane to 8 turville road in 15 mins with an average speed of 31kmph how many km did it take
0.25 x 31=7.75
How do you work out the gradient
for y-axis=highest number-lowest number
for x-axis=highest number-lowest number
gradient=difference for y-axis/difference for x-axis
How do you find the position of the median value
number of data points+1 /2
How do you find the position of the median value and then find the median in a group frequency table
number of data points+1 /2 whatever number you get add up the frequencys till you get to the number and look at what it’s asking for e.g. the number of children and whatever number you have got like 13 look across to what group that corresponds to
How do you know how to find exterior angles
exterior angles in a polygon add up to 360 degrees
each exterior angle of a polygon is 40 degrees,how many sides does it have?
360/40=9
What do you do if the angles in an exterior angle don’t add up to 360
the biggest one is most likely a reflex angle so you have to minus 180 degrees
What is the equation for pressure
force/area
What is the equation for force
area x pressure
What is something to be careful of when they ask to measure the area
sometimes they give height measurements aswell for area it is only length x width
What is the first circle theorem
angles in a segment are equal
What is the second circle theorem
The angle substended by an arc at the centre is twice the angle subtended at the circumference
What is the third circle theorem
The angle at the circumference in a semicircle is a right angle
What is the fourth circle theorem
opposite angles in a cyclic quadrilateral add up to 180 degrees
what is the fifth circle theorem
The angle between the tangent and the radius at a point on a circle is 90 degrees
What is the sixth circle theorem
2 tangents that meet at a point are the same length
What is the seventh circle theorem
The perpendicular line from the centre of a circle to a chord bisects the chord
What does the perpendicular chord bisect theorem mean
if the missing angle is on the same line as a length that runs across the center it is equal
AB and AC are tangents to a circle A=nothing,B=48,C=X work out the size of angle given that the theorem is the arc theorem
180-48=132
132/2=66
John is x years old,his sister is 16 and his brother is twice johns age all 3 siblings have a total age of 31.Write an equation and from the equation work out how old john is
x + 16 + 2x=3x+16=31
John = 5
5x-8
3x+5
What value of x makes these 2 expressions below equal
5x-8=3x+5 -3x
2x-8=5 +8
2x=13 /2
x=6.5
How do you solve an equation that is directionaly proportionate
In the equation add a k,if a=x you would add a=kx and try to work out k
R is directionally proportinate to t when R=112,T=35 work out R when T=25
112=K35 /35
112/35=3.2
3.2 X 25=80
what is the y-intercept of the equation:
y+17=12-2x
sub in 0 for x
y+17=12 -17
y=-5
What is the rule for working out the y-intercept in an equation
subsitute 0 in for x
How do you work out the co-ordiantes for the y-intercept in an equation
the x-axis is always 0 and the y-axis is the answer for y
How do you find the surface area for an object
work out each of it’s face area once you have them times each of them by 2 and add them together
what is the surface area of a cuboid box the measurments are:30,23,11
30 x 23=690
23 x 11=253
11 x 30=330
(2 x 690)+(2 x 253)+(2 x 330)=2546
What is the equation for volume
length x width x height
What unit of measurment do you measure volume in
cm cubed