Maths Chapters 6 & 7 March 2018 Flashcards
What is the equation for linear graphs?
y = m x + c
What does the ‘m’ stand for in y = m x + c?
What does the ‘c’ stand for?
m = Gradient c = where it crosses the y axis
How can you tell if two lines are parallel?
They will have the same gradient
How can we tell if two lines are perpendicular to each other?
One will have a positive gradient and the other the negative reciprocal
e.g. y = 3 x + 2 and y = -1/3 x + 19
How do perpendicular lines cross each other?
In right angles
What is the equation to work out the gradient between two lines? ( x , y ) & ( x2, y2 )
Gradient = y2 - y / x2 - x
In a distance - time graph, speed = ?
Distance / time
In a velocity - time graph, how do you work out the distance travelled?
The distance travelled is the displacement area of the graph
In a distance - time graph what is on the x and y axis?
x = distance y = time
In a velocity time graph what is on the x and y axis?
x = velocity y = time
How do you find the midpoint of any line?
( x , y ) and ( x2 , y2 )
a = ( x + x2 b = ( y + y2
/2 ) /2 )
midpoint = ( a , b )
How do you find the length of any line?
Use Pythagoras’ theorem
e.g. point 1 = ( 14 , 6 ) point 2 = ( 17 , 38 )
make a triangle with the base length of 3 (17 - 14 = 3) ‘a’ and a height of 32 (38 - 6 = 32) ‘b’. Now using Pythagoras’ theorem ( a^2 + b^2 = c^2) calculate the hypotenuse or ‘c’.
What is the equation to find out the radius of a circle on a graph?
x^2 + y^2 = r^2
How do you calculate the volume of a cylinder? Surface area?
Volume = πr^2 x h
Surface area = 2 x πr^2 + πd x h
How do you calculate the volume of a sphere? Surface area?
Volume = 4/3 x πr^3
Surface area = 4πr^2
