Page 140 - MAT KS3 Y8 Cambridge CheckPoint

13.4 Graphs in real-life contexts

7 A straight track is 400 metres long.
Two cars drive from one end to the other, in opposite
directions. Each goes at a constant speed.
One car takes 30 seconds to get from one end to 400 m
the other. The other takes 50 seconds. They both reach
the end at the same time.
Draw a graph and use it to find how far the cars are from each end of the track
when they pass one another.

Summary

You should now know that: You should be able to:
★ You can find the coordinates for any point on a ★ Construct tables of values.
coordinate grid. ★ Use all four quadrants to plot the graphs of
★ To draw a graph it is helpful to construct a table of straight lines, where y is given explicitly in terms
values. of x.
★ An equation of the form y = mx + c will always give a ★ Recognise that equations of the form y = mx + c
straight-line graph. correspond to straight-line graphs.
★ You can find the midpoint of a line segment by ★ Find the midpoint of the line segment AB, given
finding the means of the x-coordinates and the the coordinates of points A and B.
y-coordinates. ★ Draw and interpret graphs in real-life contexts
★ Graphs can be used to illustrate practical involving more than one component.
situations. Travel graphs are one example. ★ Draw accurate mathematical graphs.

138 13 Graphs