Page 98 - Knowledge Organiser Yr7 24-25

By the end of this topic you should be able to:
• Understand x and y axes
• Plot and find co-ordinates in 4 quadrants
• Use a formula to complete a table of values
• Plot points from a table of values
• Draw a graph and use it to find or estimate an unknown value
• Draw a straight line graph of a function
• Know the equation of common (horizontal and vertical) lines
Language
Meaning
Example
Co-ordinates
A pair of numbers that, together, give the position of a point
The coordinates (3,4) give the position of the point A – see below
Formula
A rule connecting different quantities. You can write a formula in words or symbols
Length = width + 3 l= w + 3
Table of values
Two rows of values that can be plotted as co-ordinates
Function
A rule that gives a unique output for
any given input. The rule is usually written as an equation
y = 2x + 1 gives an output value y for an in put value x
If x = 2 then y = 5
Equation
A function involving x and y which can be plotted on a graph using a table of values
y = 7 – 3x and y = 10x2 are both equations
Worked examples
Horizontal line
Vertical line
A line on a graph parallel to the x axis
A line on a graph parallel to the y axis
y = 1 or-3 or any constant
x = 2 or 1.5 or any constant
Straight line graph
A graph with an equation that can be written in the form y = mx + c
y = 2x + 5 is a straight line
Real life graph
A graph which can be used to illustrate a real life situation
A graph of distance vs time for your journey to school
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Knowledge Base: Mathematics TOPIC 7: Understanding Graphs Year 7 | Spring Term 2