You could be intimidated by graphs but I don’t think there’s any need. You just need to learn a few definitions and practice a few techniques to pick up some relatively easy marks.
Line Segments and Mid-points
A graph paints a thousand words:
In examples like the one above you can just use common sense to find the mid-point of a line segment like the one above but you can calculate the mid-point from just the co-ordinates of a line segment with this formula:-
So, for example a line segment AB has coordinates
A: (2, 10)
B: (10, 16)
What is the mid=point?
Using the formula from above, we have
Midpoint = ((2+10)÷2), ((10+16)÷2)
= (6, 13)
You can see this on a graph:-
Plotting Straight-Line Graphs
When you plot a linear function on a graph you get a straight line. A linear function is usually expressed in the format y= mx + b.
You can plot a linear function by feeding in values of ‘X’ and calculating ‘Y’. In theory, because a linear function will result in a straight line you only need two sets of coordinates. Normally you will be asked to calculate a few sets of coordinates in a table and then plot the line.
For example; draw the graph of y = 3x + 3 for values of x from –3 to +3
Just 3 simple steps; draw up a table, calculate the values of y and plot the graph:
Table of Values and Graph of Linear Function y = 3x + 3
To be continued…