Suppose we sketch the graph
We obtain the graph below.
We can use the graph to solve the equation
by finding the intersection of the graph with the
– axis, since this is where
Suppose we want to solve a different equation – for example,
We could sketch the graph of
and find the intersection of the graph with the– axis. It is quicker however to subtract the equation from the expression of the graph above.
minus
equals
Plotting the graph ofon the diagram above gives the diagram
The solution tois where the– values of the points where the graphs cross. These are
and