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Linear relationships – intermediate

This lesson comprises four (4) master classes focusing on:

  • Using rules, graphs and tables to explore linear relationships
  • Finding a linear relationship for a table of values
  • Gradient-intercept form
  • Solving linear equations using graphical techniques
  • Analysing linear graphs

Content:

MA4-LIN-C-01


Plot and identify points on the Cartesian plane

  • Plot and label points on the Cartesian plane of given coordinates, including those with coordinates that are not whole numbers
  • Identify and record the coordinates of given points on the Cartesian plane, including those with coordinates that are not whole numbers

Plot linear relationships on the Cartesian plane

  • Construct a geometric pattern and record the results in a table of values
  • Represent a given number pattern (including decreasing patterns) using a table of values
  • Describe a number pattern in words and generate an equation using algebraic symbols
  • Apply an equation generated from a pattern to calculate the corresponding value for a smaller or larger number
  • Recognise that a linear relationship can be represented by a number pattern, an equation (or a rule using algebraic symbols), a table of values, a set of pairs of coordinates and a line graphed on a Cartesian plane, and move flexibly between these representations
  •  Explain that there are an infinite number of ordered pairs that satisfy a given linear relationship by extending a line joining a set of points on the Cartesian plane
  •  Compare similarities and differences of multiple straight-line graphs on the same set of axes using graphing applications
  • Describe linear relationships in real-life contexts and solve related problems

Solve linear equations using graphical techniques

  • Recognise that each point on the graph of a linear relationship satisfies the equation of a line
  • Apply graphs of linear relationships to solve a corresponding linear equation using graphing applications
  • Graph 2 intersecting lines on the same set of axes and identify the point of intersection using either graphing applications or a table of values
  • Verify that the point of intersection satisfies the equations of both lines

 

MA5-LIN-C-01


Find the midpoint and gradient of a line segment (interval) on the Cartesian plane

  • Plot and join 2 points to form an interval on the Cartesian plane and use the interval as the hypotenuse of a right-angled triangle
  • Apply the relationship gradient \( m=\frac{rise}{run} \) to find the gradient/slope of the interval joining the 2 points
  • Distinguish between intervals with positive and negative gradients from a diagram
  • Explain why horizontal intervals have a gradient of 0 and vertical intervals have undefined gradients using the gradient relationship
  • Determine the midpoint of horizontal and vertical intervals on the Cartesian plane
  • Apply the process for calculating the mean to find the midpoint, of the interval joining 2 points on the Cartesian plane
  • Use graphing applications to find the midpoint and gradient/slope of an interval

Find the distance between 2 points located on the Cartesian plane

  • Use the interval between 2 points as the hypotenuse of a right-angled triangle on the Cartesian plane and apply Pythagoras’ theorem to determine the length of the interval joining the 2 points
  • Use graphing applications to find the distance between 2 points on the Cartesian plane

Recognise and graph equations

  • Recognise that equations of the form \( y=mx+c \) represent linear relationships or straight lines
  • Construct tables of values and use coordinates to graph a variety of linear relationships on the Cartesian plane, with and without digital tools
  • Identify the x- and y-intercepts of lines
  • Determine whether a point lies on a line using substitution

Examine parallel, horizontal and vertical lines

  • Explain that parallel lines have equal gradients/slopes
  • Explain why the x-axis has the equation \( y=0 \) and the y-axis has the equation \( x=0 \)
  • Recognise \( y=c \) as a line parallel to the x-axis and \( x=k \) as a line parallel to the y-axis
  • Graph vertical and horizontal lines